all: update repo to use the new error handling syntax (#8950)

cmd/tools/fast/fast.v

@@ -81,7 +81,7 @@ fn main() {
 }
 
 fn exec(s string) string {
-	e := os.exec(s) or { panic(err) }
+	e := os.exec(s) or { panic(err.msg) }
 	return e.output.trim_right('\r\n')
 }
 
@@ -111,7 +111,7 @@ fn measure(cmd string, description string) int {
 }
 
 fn measure_steps(vdir string) (int, int, int) {
-	resp := os.exec('$vdir/vprod -o v.c -show-timings $vdir/cmd/v') or { panic(err) }
+	resp := os.exec('$vdir/vprod -o v.c -show-timings $vdir/cmd/v') or { panic(err.msg) }
 	lines := resp.output.split_into_lines()
 	if lines.len != 3 {
 		return 0, 0, 0

cmd/tools/gen_vc.v

@@ -210,7 +210,7 @@ fn (mut gen_vc GenVC) generate() {
 	// check if gen_vc dir exists
 	if !os.is_dir(gen_vc.options.work_dir) {
 		// try create
-		os.mkdir(gen_vc.options.work_dir) or { panic(err) }
+		os.mkdir(gen_vc.options.work_dir) or { panic(err.msg) }
 		// still dosen't exist... we have a problem
 		if !os.is_dir(gen_vc.options.work_dir) {
 			gen_vc.logger.error('error creating directory: $gen_vc.options.work_dir')
@@ -246,8 +246,8 @@ fn (mut gen_vc GenVC) generate() {
 	ts_v := git_log_v.find_between('Date:', '\n').trim_space()
 	ts_vc := git_log_vc.find_between('Date:', '\n').trim_space()
 	// parse time as string to time.Time
-	last_commit_time_v := time.parse(ts_v) or { panic(err) }
+	last_commit_time_v := time.parse(ts_v) or { panic(err.msg) }
-	last_commit_time_vc := time.parse(ts_vc) or { panic(err) }
+	last_commit_time_vc := time.parse(ts_vc) or { panic(err.msg) }
 	// git dates are in users local timezone and v time.parse does not parse
 	// timezones at the moment, so for now get unix timestamp from output also
 	t_unix_v := git_log_v.find_between('Date Unix:', '\n').trim_space().int()
@@ -320,7 +320,7 @@ fn (mut gen_vc GenVC) command_execute(cmd string, dry bool) string {
 	gen_vc.logger.info('cmd: $cmd')
 	r := os.exec(cmd) or {
 		gen_vc.logger.error('$err_msg_cmd_x: "$cmd" could not start.')
-		gen_vc.logger.error(err)
+		gen_vc.logger.error(err.msg)
 		// something went wrong, better start fresh next time
 		gen_vc.purge_repos()
 		gen_vc.gen_error = true

cmd/tools/missdoc.v

@@ -55,7 +55,7 @@ fn report_undocumented_functions_in_path(opt Options, path string) {
 }
 
 fn report_undocumented_functions_in_file(opt Options, file string) {
-	contents := os.read_file(file) or { panic(err) }
+	contents := os.read_file(file) or { panic(err.msg) }
 	lines := contents.split('\n')
 	mut info := []UndocumentedFN{}
 	for i, line in lines {

cmd/tools/modules/scripting/scripting.v

@@ -53,9 +53,9 @@ pub fn rmrf(path string) {
 	verbose_trace(@FN, 'rm -rf $path')
 	if os.exists(path) {
 		if os.is_dir(path) {
-			os.rmdir_all(path) or { panic(err) }
+			os.rmdir_all(path) or { panic(err.msg) }
 		} else {
-			os.rm(path) or { panic(err) }
+			os.rm(path) or { panic(err.msg) }
 		}
 	}
 }
@@ -64,7 +64,7 @@ pub fn exec(cmd string) ?os.Result {
 	verbose_trace(@FN, cmd)
 	x := os.exec(cmd) or {
 		verbose_trace(@FN, '## failed.')
-		return error(err)
+		return err
 	}
 	verbose_trace_exec_result(x)
 	return x

cmd/tools/modules/testing/common.v

@@ -221,7 +221,7 @@ pub fn (mut ts TestSession) test() {
 	// cleanup generated .tmp.c files after successfull tests:
 	if ts.benchmark.nfail == 0 {
 		if ts.rm_binaries {
-			os.rmdir_all(ts.vtmp_dir) or { panic(err) }
+			os.rmdir_all(ts.vtmp_dir) or { panic(err.msg) }
 		}
 	}
 }
@@ -255,7 +255,7 @@ fn worker_trunner(mut p pool.PoolProcessor, idx int, thread_id int) voidptr {
 	generated_binary_fpath := os.join_path(tmpd, generated_binary_fname)
 	if os.exists(generated_binary_fpath) {
 		if ts.rm_binaries {
-			os.rm(generated_binary_fpath) or { panic(err) }
+			os.rm(generated_binary_fpath) or { panic(err.msg) }
 		}
 	}
 	mut cmd_options := [ts.vargs]
@@ -308,7 +308,7 @@ fn worker_trunner(mut p pool.PoolProcessor, idx int, thread_id int) voidptr {
 	}
 	if os.exists(generated_binary_fpath) {
 		if ts.rm_binaries {
-			os.rm(generated_binary_fpath) or { panic(err) }
+			os.rm(generated_binary_fpath) or { panic(err.msg) }
 		}
 	}
 	return pool.no_result
@@ -358,7 +358,7 @@ pub fn prepare_test_session(zargs string, folder string, oskipped []string, main
 				continue
 			}
 		}
-		c := os.read_file(f) or { panic(err) }
+		c := os.read_file(f) or { panic(err.msg) }
 		maxc := if c.len > 300 { 300 } else { c.len }
 		start := c[0..maxc]
 		if start.contains('module ') && !start.contains('module main') {
@@ -436,7 +436,7 @@ pub fn header(msg string) {
 pub fn setup_new_vtmp_folder() string {
 	now := time.sys_mono_now()
 	new_vtmp_dir := os.join_path(os.temp_dir(), 'v', 'test_session_$now')
-	os.mkdir_all(new_vtmp_dir) or { panic(err) }
+	os.mkdir_all(new_vtmp_dir) or { panic(err.msg) }
 	os.setenv('VTMP', new_vtmp_dir, true)
 	return new_vtmp_dir
 }

cmd/tools/oldv.v

@@ -101,7 +101,7 @@ fn main() {
 	scripting.cprintln('#   checkout folder: $context.path_v')
 	if context.cmd_to_run.len > 0 {
 		cmdres := os.exec(context.cmd_to_run) or {
-			panic(err)
+			panic(err.msg)
 		}
 		scripting.cprintln('#           command: ${context.cmd_to_run:-34s} exit code: ${cmdres.exit_code:-4d}  result:')
 		println(cmdres.output)

cmd/tools/test_if_v_test_system_works.v

@@ -28,16 +28,16 @@ fn get_vexe_path() string {
 fn new_tdir() string {
 	tdir_ := os.join_path(os.temp_dir(), rand.ulid())
 	if os.exists(tdir_) {
-		os.rmdir(tdir_) or { panic(err) }
+		os.rmdir(tdir_) or { panic(err.msg) }
 	}
-	os.mkdir(tdir_) or { panic(err) }
+	os.mkdir(tdir_) or { panic(err.msg) }
 	C.atexit(cleanup_tdir)
 	return tdir_
 }
 
 fn cleanup_tdir() {
 	println('... removing tdir: $tdir')
-	os.rmdir_all(tdir) or { panic(err) }
+	os.rmdir_all(tdir) or { panic(err.msg) }
 }
 
 fn main() {
@@ -55,7 +55,7 @@ fn main() {
 
 fn check_ok(cmd string) string {
 	println('>   check_ok cmd: $cmd')
-	res := os.exec(cmd) or { panic(err) }
+	res := os.exec(cmd) or { panic(err.msg) }
 	if res.exit_code != 0 {
 		eprintln('>   check_ok failed.\n$res.output')
 		exit(1)
@@ -65,7 +65,7 @@ fn check_ok(cmd string) string {
 
 fn check_fail(cmd string) string {
 	println('> check_fail cmd: $cmd')
-	res := os.exec(cmd) or { panic(err) }
+	res := os.exec(cmd) or { panic(err.msg) }
 	if res.exit_code == 0 {
 		eprintln('> check_fail succeeded, but it should have failed.\n$res.output')
 		exit(1)

cmd/tools/vbin2v.v

@@ -108,7 +108,7 @@ fn main() {
 		exit(0)
 	}
 	files := fp.finalize() or {
-		eprintln('Error: ' + err)
+		eprintln('Error: $err')
 		exit(1)
 	}
 	real_files := files.filter(it != 'bin2v')

cmd/tools/vbuild-tools.v

@@ -55,11 +55,11 @@ fn main() {
 		//
 		tpath := os.join_path(session.vtmp_dir, texe)
 		if tname in tools_in_subfolders {
-			os.mv_by_cp(tpath, os.join_path(tfolder, tname, texe)) or { panic(err) }
+			os.mv_by_cp(tpath, os.join_path(tfolder, tname, texe)) or { panic(err.msg) }
 			continue
 		}
 		os.mv_by_cp(tpath, os.join_path(tfolder, texe)) or {
-			if !err.contains('vbuild-tools') {
+			if !err.msg.contains('vbuild-tools') {
 				eprintln(err)
 			}
 			continue

cmd/tools/vcheck-md.v

@@ -244,7 +244,7 @@ fn (mut f MDFile) check_examples() (int, int) {
 		mut should_cleanup_vfile := true
 		// eprintln('>>> checking example $vfile ...')
 		vcontent := e.text.join('\n') + '\n'
-		os.write_file(vfile, vcontent) or { panic(err) }
+		os.write_file(vfile, vcontent) or { panic(err.msg) }
 		mut acommands := e.command.split(' ')
 		nofmt := 'nofmt' in acommands
 		for command in acommands {
@@ -331,7 +331,7 @@ fn (mut f MDFile) check_examples() (int, int) {
 			}
 		}
 		if should_cleanup_vfile {
-			os.rm(vfile) or { panic(err) }
+			os.rm(vfile) or { panic(err.msg) }
 		}
 	}
 	return errors, oks

cmd/tools/vcreate.v

@@ -55,10 +55,10 @@ fn gen_gitignore(name string) string {
 fn (c &Create) write_vmod(new bool) {
 	vmod_path := if new { '$c.name/v.mod' } else { 'v.mod' }
 	mut vmod := os.create(vmod_path) or {
-		cerror(err)
+		cerror(err.msg)
 		exit(1)
 	}
-	vmod.write_str(vmod_content(c.name, c.description)) or { panic(err) }
+	vmod.write_str(vmod_content(c.name, c.description)) or { panic(err.msg) }
 	vmod.close()
 }
 
@@ -68,10 +68,10 @@ fn (c &Create) write_main(new bool) {
 	}
 	main_path := if new { '$c.name/${c.name}.v' } else { '${c.name}.v' }
 	mut mainfile := os.create(main_path) or {
-		cerror(err)
+		cerror(err.msg)
 		exit(2)
 	}
-	mainfile.write_str(main_content()) or { panic(err) }
+	mainfile.write_str(main_content()) or { panic(err.msg) }
 	mainfile.close()
 }
 
@@ -87,7 +87,7 @@ fn (c &Create) create_git_repo(dir string) {
 				// We don't really need a .gitignore, it's just a nice-to-have
 				return
 			}
-			fl.write_str(gen_gitignore(c.name)) or { panic(err) }
+			fl.write_str(gen_gitignore(c.name)) or { panic(err.msg) }
 			fl.close()
 		}
 	}
@@ -110,7 +110,7 @@ fn create() {
 	}
 	c.description = os.input('Input your project description: ')
 	println('Initialising ...')
-	os.mkdir(c.name) or { panic(err) }
+	os.mkdir(c.name) or { panic(err.msg) }
 	c.write_vmod(true)
 	c.write_main(true)
 	c.create_git_repo(c.name)

cmd/tools/vdoc/html.v

@@ -126,7 +126,7 @@ fn (vd VDoc) render_search_index(out Output) {
 	js_search_index.writeln('];')
 	js_search_data.writeln('];')
 	out_file_path := os.join_path(out.path, 'search_index.js')
-	os.write_file(out_file_path, js_search_index.str() + js_search_data.str()) or { panic(err) }
+	os.write_file(out_file_path, js_search_index.str() + js_search_data.str()) or { panic(err.msg) }
 }
 
 fn (mut vd VDoc) render_static_html(out Output) {
@@ -162,7 +162,7 @@ fn (vd VDoc) get_resource(name string, out Output) string {
 		output_path := os.join_path(out.path, name)
 		if !os.exists(output_path) {
 			println('Generating $out.typ in "$output_path"')
-			os.write_file(output_path, res) or { panic(err) }
+			os.write_file(output_path, res) or { panic(err.msg) }
 		}
 		return name
 	}

cmd/tools/vdoc/vdoc.v

@@ -162,7 +162,7 @@ fn (vd VDoc) work_processor(mut work sync.Channel, mut wg sync.WaitGroup) {
 		file_name, content := vd.render_doc(pdoc.d, pdoc.out)
 		output_path := os.join_path(pdoc.out.path, file_name)
 		println('Generating $pdoc.out.typ in "$output_path"')
-		os.write_file(output_path, content) or { panic(err) }
+		os.write_file(output_path, content) or { panic(err.msg) }
 	}
 	wg.done()
 }
@@ -350,15 +350,15 @@ fn (mut vd VDoc) generate_docs_from_file() {
 			out.path = os.real_path('.')
 		}
 		if !os.exists(out.path) {
-			os.mkdir(out.path) or { panic(err) }
+			os.mkdir(out.path) or { panic(err.msg) }
 		}
 		if cfg.is_multi {
 			out.path = os.join_path(out.path, '_docs')
 			if !os.exists(out.path) {
-				os.mkdir(out.path) or { panic(err) }
+				os.mkdir(out.path) or { panic(err.msg) }
 			} else {
 				for fname in css_js_assets {
-					os.rm(os.join_path(out.path, fname)) or { panic(err) }
+					os.rm(os.join_path(out.path, fname)) or { panic(err.msg) }
 				}
 			}
 		}
@@ -372,11 +372,11 @@ fn (mut vd VDoc) generate_docs_from_file() {
 			vd.render_search_index(out)
 			// move favicons to target directory
 			println('Copying favicons...')
-			favicons := os.ls(favicons_path) or { panic(err) }
+			favicons := os.ls(favicons_path) or { panic(err.msg) }
 			for favicon in favicons {
 				favicon_path := os.join_path(favicons_path, favicon)
 				destination_path := os.join_path(out.path, favicon)
-				os.cp(favicon_path, destination_path) or { panic(err) }
+				os.cp(favicon_path, destination_path) or { panic(err.msg) }
 			}
 		}
 	}

cmd/tools/vfmt.v

@@ -175,7 +175,7 @@ fn (foptions &FormatOptions) format_file(file string) {
 	file_name := os.file_name(file)
 	ulid := rand.ulid()
 	vfmt_output_path := os.join_path(vtmp_folder, 'vfmt_${ulid}_$file_name')
-	os.write_file(vfmt_output_path, formatted_content) or { panic(err) }
+	os.write_file(vfmt_output_path, formatted_content) or { panic(err.msg) }
 	if foptions.is_verbose {
 		eprintln('fmt.fmt worked and $formatted_content.len bytes were written to $vfmt_output_path .')
 	}
@@ -266,7 +266,7 @@ fn (foptions &FormatOptions) post_process_file(file string, formatted_file_path
 	}
 	if foptions.is_w {
 		if is_formatted_different {
-			os.mv_by_cp(formatted_file_path, file) or { panic(err) }
+			os.mv_by_cp(formatted_file_path, file) or { panic(err.msg) }
 			eprintln('Reformatted file: $file')
 		} else {
 			eprintln('Already formatted file: $file')
@@ -312,7 +312,7 @@ fn get_compile_name_of_potential_v_project(file string) string {
 	pfolder := os.real_path(os.dir(file))
 	// a .v project has many 'module main' files in one folder
 	// if there is only one .v file, then it must be a standalone
-	all_files_in_pfolder := os.ls(pfolder) or { panic(err) }
+	all_files_in_pfolder := os.ls(pfolder) or { panic(err.msg) }
 	mut vfiles := []string{}
 	for f in all_files_in_pfolder {
 		vf := os.join_path(pfolder, f)
@@ -332,7 +332,7 @@ fn get_compile_name_of_potential_v_project(file string) string {
 	// a project folder, that should be compiled with `v pfolder`.
 	mut main_fns := 0
 	for f in vfiles {
-		slines := read_source_lines(f) or { panic(err) }
+		slines := read_source_lines(f) or { panic(err.msg) }
 		for line in slines {
 			if line.contains('fn main()') {
 				main_fns++

cmd/tools/vpm.v

@@ -71,7 +71,7 @@ fn main() {
 		'install' {
 			if module_names.len == 0 && os.exists('./v.mod') {
 				println('Detected v.mod file inside the project directory. Using it...')
-				manifest := vmod.from_file('./v.mod') or { panic(err) }
+				manifest := vmod.from_file('./v.mod') or { panic(err.msg) }
 				module_names = manifest.dependencies
 			}
 			vpm_install(module_names)
@@ -331,13 +331,13 @@ fn vpm_remove(module_names []string) {
 		final_module_path := valid_final_path_of_existing_module(name) or { continue }
 		println('Removing module "$name"...')
 		verbose_println('removing folder $final_module_path')
-		os.rmdir_all(final_module_path) or { panic(err) }
+		os.rmdir_all(final_module_path) or { panic(err.msg) }
 		// delete author directory if it is empty
 		author := name.split('.')[0]
 		author_dir := os.real_path(os.join_path(settings.vmodules_path, author))
 		if os.is_dir_empty(author_dir) {
 			verbose_println('removing author folder $author_dir')
-			os.rmdir(author_dir) or { panic(err) }
+			os.rmdir(author_dir) or { panic(err.msg) }
 		}
 	}
 }
@@ -364,7 +364,7 @@ fn valid_final_path_of_existing_module(name string) ?string {
 fn ensure_vmodules_dir_exist() {
 	if !os.is_dir(settings.vmodules_path) {
 		println('Creating $settings.vmodules_path/ ...')
-		os.mkdir(settings.vmodules_path) or { panic(err) }
+		os.mkdir(settings.vmodules_path) or { panic(err.msg) }
 	}
 }
 
@@ -411,7 +411,7 @@ fn get_installed_modules() []string {
 
 fn get_all_modules() []string {
 	url := get_working_server_url()
-	r := http.get(url) or { panic(err) }
+	r := http.get(url) or { panic(err.msg) }
 	if r.status_code != 200 {
 		println('Failed to search vpm.vlang.io. Status code: $r.status_code')
 		exit(1)

cmd/tools/vrepl.v

@@ -184,7 +184,7 @@ fn run_repl(workdir string, vrepl_prefix string) {
 		}
 		if r.line.starts_with('print') {
 			source_code := r.current_source_code(false) + '\n$r.line\n'
-			os.write_file(file, source_code) or { panic(err) }
+			os.write_file(file, source_code) or { panic(err.msg) }
 			s := repl_run_vfile(file) or { return }
 			print_output(s)
 		} else {
@@ -251,7 +251,7 @@ fn run_repl(workdir string, vrepl_prefix string) {
 				}
 				temp_source_code = r.current_source_code(true) + '\n$temp_line\n'
 			}
-			os.write_file(temp_file, temp_source_code) or { panic(err) }
+			os.write_file(temp_file, temp_source_code) or { panic(err.msg) }
 			s := repl_run_vfile(temp_file) or { return }
 			if !func_call && s.exit_code == 0 && !temp_flag {
 				for r.temp_lines.len > 0 {
@@ -355,8 +355,8 @@ fn repl_run_vfile(file string) ?os.Result {
 		eprintln('>> repl_run_vfile file: $file')
 	}
 	s := os.exec('"$vexe" -repl run "$file"') or {
-		rerror(err)
+		rerror(err.msg)
-		return error(err)
+		return err
 	}
 	return s
 }

cmd/tools/vself.v

@@ -27,12 +27,12 @@ fn main() {
 		// The user just wants an independent copy of v, and so we are done.
 		return
 	}
-	backup_old_version_and_rename_newer() or { panic(err) }
+	backup_old_version_and_rename_newer() or { panic(err.msg) }
 	println('V built successfully!')
 }
 
 fn compile(vroot string, cmd string) {
-	result := os.exec(cmd) or { panic(err) }
+	result := os.exec(cmd) or { panic(err.msg) }
 	if result.exit_code != 0 {
 		eprintln('cannot compile to `$vroot`: \n$result.output')
 		exit(1)
@@ -76,7 +76,7 @@ fn backup_old_version_and_rename_newer() ?bool {
 	os.rm(v_file) or { }
 
 	list_folder('', 'moving $v2_file to $v_file ...')
-	os.mv_by_cp(v2_file, v_file) or { panic(err) }
+	os.mv_by_cp(v2_file, v_file) or { panic(err.msg) }
 
 	list_folder('after:', '')
 

cmd/tools/vsetup-freetype.v

@@ -12,7 +12,7 @@ fn main() {
 			println('Thirdparty "freetype" is already installed.')
 		} else {
 			s := os.exec('git clone --depth=1 https://github.com/ubawurinna/freetype-windows-binaries ./thirdparty/freetype/') or {
-				panic(err)
+				panic(err.msg)
 			}
 			println(s.output)
 			println('Thirdparty "freetype" installed successfully.')

cmd/tools/vsymlink.v

@@ -27,11 +27,11 @@ fn setup_symlink_unix(vexe string) {
 	if os.system("uname -o | grep -q '[A/a]ndroid'") == 1 {
 		link_dir := '/usr/local/bin'
 		if !os.exists(link_dir) {
-			os.mkdir_all(link_dir) or { panic(err) }
+			os.mkdir_all(link_dir) or { panic(err.msg) }
 		}
 		link_path = link_dir + '/v'
 	}
-	ret := os.exec('ln -sf $vexe $link_path') or { panic(err) }
+	ret := os.exec('ln -sf $vexe $link_path') or { panic(err.msg) }
 	if ret.exit_code == 0 {
 		println('Symlink "$link_path" has been created')
 	} else {
@@ -49,14 +49,14 @@ fn setup_symlink_windows(vexe string) {
 		mut vsymlink := os.join_path(vsymlinkdir, 'v.exe')
 		// Remove old symlink first (v could have been moved, symlink rerun)
 		if !os.exists(vsymlinkdir) {
-			os.mkdir(vsymlinkdir) or { panic(err) }
+			os.mkdir(vsymlinkdir) or { panic(err.msg) }
 		} else {
 			if os.exists(vsymlink) {
-				os.rm(vsymlink) or { panic(err) }
+				os.rm(vsymlink) or { panic(err.msg) }
 			} else {
 				vsymlink = os.join_path(vsymlinkdir, 'v.bat')
 				if os.exists(vsymlink) {
-					os.rm(vsymlink) or { panic(err) }
+					os.rm(vsymlink) or { panic(err.msg) }
 				}
 				vsymlink = os.join_path(vsymlinkdir, 'v.exe')
 			}
@@ -69,9 +69,9 @@ fn setup_symlink_windows(vexe string) {
 			eprintln('Creating a batch file instead...')
 			vsymlink = os.join_path(vsymlinkdir, 'v.bat')
 			if os.exists(vsymlink) {
-				os.rm(vsymlink) or { panic(err) }
+				os.rm(vsymlink) or { panic(err.msg) }
 			}
-			os.write_file(vsymlink, '@echo off\n$vexe %*') or { panic(err) }
+			os.write_file(vsymlink, '@echo off\n$vexe %*') or { panic(err.msg) }
 			eprintln('$vsymlink file written.')
 		}
 		if !os.exists(vsymlink) {
@@ -80,7 +80,7 @@ fn setup_symlink_windows(vexe string) {
 		println('Symlink $vsymlink to $vexe created.')
 		println('Checking system %PATH%...')
 		reg_sys_env_handle := get_reg_sys_env_handle() or {
-			warn_and_exit(err)
+			warn_and_exit(err.msg)
 			return
 		}
 		// TODO: Fix defers inside ifs
@@ -107,7 +107,7 @@ fn setup_symlink_windows(vexe string) {
 			println('Adding symlink directory to system %PATH%...')
 			set_reg_value(reg_sys_env_handle, 'Path', new_sys_env_path) or {
 				C.RegCloseKey(reg_sys_env_handle)
-				warn_and_exit(err)
+				warn_and_exit(err.msg)
 			}
 			println('Done.')
 		}

cmd/tools/vtest-parser.v

@@ -124,7 +124,7 @@ fn process_cli_args() &Context {
 		exit(0)
 	}
 	context.all_paths = fp.finalize() or {
-		context.error(err)
+		context.error(err.msg)
 		exit(1)
 	}
 	if !context.is_worker && context.all_paths.len == 0 {
@@ -218,7 +218,7 @@ fn (mut context Context) process_whole_file_in_worker(path string) (int, int) {
 		cmd := '"$context.myself" $verbosity --worker --timeout_ms ${context.timeout_ms:5} --cut_index ${i:5} --path "$path" '
 		context.log(cmd)
 		res := os.exec(cmd) or { os.Result{
-			output: err
+			output: err.msg
 			exit_code: ecode_exec
 		} }
 		context.log('worker exit_code: $res.exit_code | worker output:\n$res.output')

cmd/tools/vup.v

@@ -41,7 +41,7 @@ fn main() {
 		app.backup('cmd/tools/vup.exe')
 	}
 	app.recompile_v()
-	os.exec('"$app.vexe" cmd/tools/vup.v') or { panic(err) }
+	os.exec('"$app.vexe" cmd/tools/vup.v') or { panic(err.msg) }
 	app.show_current_v_version()
 }
 
@@ -88,7 +88,7 @@ fn (app App) make(vself string) {
 	$if windows {
 		make = 'make.bat'
 	}
-	make_result := os.exec(make) or { panic(err) }
+	make_result := os.exec(make) or { panic(err.msg) }
 	app.vprintln(make_result.output)
 }
 
@@ -121,7 +121,7 @@ fn (app App) git_command(command string) {
 	git_result := os.exec('git $command') or {
 		app.get_git()
 		// Try it again with (maybe) git installed
-		os.exec('git $command') or { panic(err) }
+		os.exec('git $command') or { panic(err.msg) }
 	}
 	if git_result.exit_code != 0 {
 		eprintln(git_result.output)
@@ -136,11 +136,11 @@ fn (app App) get_git() {
 		// We'll use 32 bit because maybe someone out there is using 32-bit windows
 		os.exec('bitsadmin.exe /transfer "vgit" https://github.com/git-for-windows/git/releases/download/v2.30.0.windows.2/Git-2.30.0.2-32-bit.exe "$os.getwd()/git32.exe"') or {
 			eprintln('Unable to install git automatically: please install git manually')
-			panic(err)
+			panic(err.msg)
 		}
 		os.exec('$os.getwd()/git32.exe') or {
 			eprintln('Unable to install git automatically: please install git manually')
-			panic(err)
+			panic(err.msg)
 		}
 	} $else { // Probably some kind of *nix, usually need to get using a package manager.
 		eprintln("error: Install `git` using your system's package manager")

cmd/tools/vvet/vet_test.v

@@ -21,7 +21,7 @@ fn test_vet() {
 }
 
 fn get_tests_in_dir(dir string) []string {
-	files := os.ls(dir) or { panic(err) }
+	files := os.ls(dir) or { panic(err.msg) }
 	mut tests := files.filter(it.ends_with('.vv'))
 	tests.sort()
 	return tests
@@ -34,8 +34,8 @@ fn check_path(vexe string, dir string, tests []string) int {
 		program := path
 		print(path + ' ')
 		// -force is needed so that `v vet` would not skip the regression files
-		res := os.exec('$vexe vet -force $program') or { panic(err) }
+		res := os.exec('$vexe vet -force $program') or { panic(err.msg) }
-		mut expected := os.read_file(program.replace('.vv', '') + '.out') or { panic(err) }
+		mut expected := os.read_file(program.replace('.vv', '') + '.out') or { panic(err.msg) }
 		expected = clean_line_endings(expected)
 		found := clean_line_endings(res.output)
 		if expected != found {

doc/docs.md

@@ -1321,7 +1321,7 @@ import os
 
 fn read_log() {
 	mut ok := false
-	mut f := os.open('log.txt') or { panic(err) }
+	mut f := os.open('log.txt') or { panic(err.msg) }
 	defer {
 		f.close()
 	}
@@ -2401,7 +2401,7 @@ any further.
 The body of `f` is essentially a condensed version of:
 
 ```v ignore
-    resp := http.get(url) or { return error(err) }
+    resp := http.get(url) or { return err }
     return resp.text
 ```
 
@@ -2418,7 +2418,7 @@ to break from the current block.
 Note that `break` and `continue` can only be used inside a `for` loop.
 
 V does not have a way to forcibly "unwrap" an optional (as other languages do,
-for instance Rust's `unwrap()` or Swift's `!`). To do this, use `or { panic(err) }` instead.
+for instance Rust's `unwrap()` or Swift's `!`). To do this, use `or { panic(err.msg) }` instead.
 
 ---
 The third method is to provide a default value at the end of the `or` block.
@@ -3495,7 +3495,7 @@ Full list of builtin options:
 module main
 fn main() {
 	embedded_file := $embed_file('v.png')
-	mut fw := os.create('exported.png') or { panic(err) }
+	mut fw := os.create('exported.png') or { panic(err.msg) }
 	fw.write_bytes(embedded_file.data(), embedded_file.len)
 	fw.close()
 }
@@ -3658,7 +3658,7 @@ eprintln('file: ' + @FILE + ' | line: ' + @LINE + ' | fn: ' + @MOD + '.' + @FN)
 Another example, is if you want to embed the version/name from v.mod *inside* your executable:
 ```v ignore
 import v.vmod
-vm := vmod.decode( @VMOD_FILE ) or { panic(err) }
+vm := vmod.decode( @VMOD_FILE ) or { panic(err.msg) }
 eprintln('$vm.name $vm.version\n $vm.description')
 ```
 

examples/database/orm.v

@@ -16,7 +16,7 @@ struct User {
 }
 
 fn main() {
-	db := sqlite.connect(':memory:') or { panic(err) }
+	db := sqlite.connect(':memory:') or { panic(err.msg) }
 	db.exec('drop table if exists User')
 	db.exec("create table Module (id integer primary key, name text default '', nr_downloads int default 0, creator int default 0);")
 	db.exec("create table User (id integer primary key, age int default 0, name text default '', is_customer int default 0);")

examples/database/pg/customer.v

@@ -41,7 +41,7 @@ fn main() {
 
 	// by adding `limit 1` we tell V that there will be only one object
 	println(dash)
-	existing := db.select from Customer where id == 1 limit 1 or { panic(err) }
+	existing := db.select from Customer where id == 1 limit 1 or { panic(err.msg) }
 	println('Existing customer name: $existing.name')
 	println('Existing customer full information:')
 	println(existing)

examples/flappylearning/game.v

@@ -212,13 +212,13 @@ fn (mut app App) run() {
 
 fn init_images(mut app App) {
 	$if android {
-		background := os.read_apk_asset('img/background.png') or { panic(err) }
+		background := os.read_apk_asset('img/background.png') or { panic(err.msg) }
 		app.background = app.gg.create_image_from_byte_array(background)
-		bird := os.read_apk_asset('img/bird.png') or { panic(err) }
+		bird := os.read_apk_asset('img/bird.png') or { panic(err.msg) }
 		app.bird = app.gg.create_image_from_byte_array(bird)
-		pipetop := os.read_apk_asset('img/pipetop.png') or { panic(err) }
+		pipetop := os.read_apk_asset('img/pipetop.png') or { panic(err.msg) }
 		app.pipetop = app.gg.create_image_from_byte_array(pipetop)
-		pipebottom := os.read_apk_asset('img/pipebottom.png') or { panic(err) }
+		pipebottom := os.read_apk_asset('img/pipebottom.png') or { panic(err.msg) }
 		app.pipebottom = app.gg.create_image_from_byte_array(pipebottom)
 	} $else {
 		app.background = app.gg.create_image(os.resource_abs_path('assets/img/background.png'))

examples/path_tracing.v

@@ -98,15 +98,15 @@ fn new_image(w int, h int) Image {
 // write out a .ppm file
 fn (image Image) save_as_ppm(file_name string) {
 	npixels := image.width * image.height
-	mut f_out := os.create(file_name) or { panic(err) }
+	mut f_out := os.create(file_name) or { panic(err.msg) }
-	f_out.writeln('P3') or { panic(err) }
+	f_out.writeln('P3') or { panic(err.msg) }
-	f_out.writeln('$image.width $image.height') or { panic(err) }
+	f_out.writeln('$image.width $image.height') or { panic(err.msg) }
-	f_out.writeln('255') or { panic(err) }
+	f_out.writeln('255') or { panic(err.msg) }
 	for i in 0 .. npixels {
 		c_r := to_int(unsafe { image.data[i] }.x)
 		c_g := to_int(unsafe { image.data[i] }.y)
 		c_b := to_int(unsafe { image.data[i] }.z)
-		f_out.write_str('$c_r $c_g $c_b ') or { panic(err) }
+		f_out.write_str('$c_r $c_g $c_b ') or { panic(err.msg) }
 	}
 	f_out.close()
 }

examples/process/command.v

@@ -10,7 +10,7 @@ fn exec(path string) string {
 	mut cmd := os.Command{
 		path: path
 	}
-	cmd.start() or { panic(err) }
+	cmd.start() or { panic(err.msg) }
 
 	for {
 		line = cmd.read_line()

examples/process/execve.v

@@ -5,7 +5,7 @@ import os
 fn exec(args []string) {
 	os.execve('/bin/bash', args, []) or {
 		// eprintln(err)
-		panic(err)
+		panic(err.msg)
 	}
 }
 

examples/process/process_script.v

@@ -47,7 +47,7 @@ echo redirect 1 to 2  1>&2
 echo line 3
 '
 
-	os.write_file('/tmp/test.sh', script) or { panic(err) }
+	os.write_file('/tmp/test.sh', script) or { panic(err.msg) }
 	// os.chmod("/tmp/test.sh",0o700) //make executable
 
 	// this will work because stderr/stdout are smaller than 4096 chars, once larger there can be deadlocks

examples/regex/regex_example.v

@@ -20,12 +20,12 @@ fn convert_html_rgb(in_col string) u32 {
 	mut col_mul := if in_col.len == 4 { 4 } else { 0 }
 
 	// this is the regex query, it uses V string interpolation to customize the regex query
-	// NOTE: if you want use escaped code you must use the r"" (raw) strings, 
+	// NOTE: if you want use escaped code you must use the r"" (raw) strings,
 	//       *** please remember that V interpoaltion doesn't work on raw strings. ***
 
 	query := '#([a-fA-F0-9]{$n_digit})([a-fA-F0-9]{$n_digit})([a-fA-F0-9]{$n_digit})'
 
-	mut re := regex.regex_opt(query) or { panic(err) }
+	mut re := regex.regex_opt(query) or { panic(err.msg) }
 	start, end := re.match_string(in_col)
 	println('start: $start, end: $end')
 	mut res := u32(0)
@@ -49,7 +49,7 @@ fn convert_html_rgb_n(in_col string) u32 {
 
 	query := '#(?P<red>[a-fA-F0-9]{$n_digit})(?P<green>[a-fA-F0-9]{$n_digit})(?P<blue>[a-fA-F0-9]{$n_digit})'
 
-	mut re := regex.regex_opt(query) or { panic(err) }
+	mut re := regex.regex_opt(query) or { panic(err.msg) }
 	start, end := re.match_string(in_col)
 	println('start: $start, end: $end')
 	mut res := u32(0)

examples/templates/templates.v

@@ -171,12 +171,12 @@ fn data_get() []SiteConfig {
 
 fn data_dump(data []SiteConfig) {
 	a := json.encode_pretty(data)
-	os.write_file(os.resource_abs_path('data.json'), a) or { panic(err) }
+	os.write_file(os.resource_abs_path('data.json'), a) or { panic(err.msg) }
 }
 
 fn data_load() []SiteConfig {
-	data := os.read_file(os.resource_abs_path('data.json')) or { panic(err) }
+	data := os.read_file(os.resource_abs_path('data.json')) or { panic(err.msg) }
-	a := json.decode([]SiteConfig, data) or { panic(err) }
+	a := json.decode([]SiteConfig, data) or { panic(err.msg) }
 	return a
 }
 
@@ -192,5 +192,5 @@ fn main() {
 	// data_dump(data)
 	b := filled_in_template()
 	println(b)
-	os.write_file('result.md', b) or { panic(err) }
+	os.write_file('result.md', b) or { panic(err.msg) }
 }

examples/term.ui/text_editor.v

@@ -44,7 +44,7 @@ fn (mut a App) set_status(msg string, duration_ms int) {
 fn (mut a App) save() {
 	if a.cfile().len > 0 {
 		b := a.ed
-		os.write_file(a.cfile(), b.raw()) or { panic(err) }
+		os.write_file(a.cfile(), b.raw()) or { panic(err.msg) }
 		a.set_status('Saved', 2000)
 	} else {
 		a.set_status('No file loaded', 4000)
@@ -456,7 +456,7 @@ fn (mut a App) init_file() {
 			// 'vico: ' +
 			a.tui.set_window_title(a.files[a.current_file])
 			mut b := a.ed
-			content := os.read_file(a.files[a.current_file]) or { panic(err) }
+			content := os.read_file(a.files[a.current_file]) or { panic(err.msg) }
 			b.put(content)
 			a.ed.cursor.pos_x = init_x
 			a.ed.cursor.pos_y = init_y

examples/ttf_font/example_ttf.v

@@ -135,7 +135,7 @@ fn main() {
 	// load TTF fonts
 	for font_path in font_paths {
 		mut tf := ttf.TTF_File{}
-		tf.buf = os.read_bytes(font_path) or { panic(err) }
+		tf.buf = os.read_bytes(font_path) or { panic(err.msg) }
 		println('TrueTypeFont file [$font_path] len: $tf.buf.len')
 		tf.init()
 		println('Unit per EM: $tf.units_per_em')

examples/v_script.vsh

@@ -12,14 +12,14 @@ mkdir('v_script_dir')
 
 println("\nEntering into v_script_dir and listing it's files.")
 chdir('v_script_dir')
-files := ls('.') or { panic(err) }
+files := ls('.') or { panic(err.msg) }
 println(files)
 
 println('\nCreating foo.txt')
 create('foo.txt')?
 
 println('\nFiles:')
-again_ls := ls('.') or { panic(err) }
+again_ls := ls('.') or { panic(err.msg) }
 println(again_ls)
 
 println('\nRemoving foo.txt and v_script_dir')

examples/websocket/client-server/server.v

@@ -28,7 +28,7 @@ fn start_server() ? {
 		for i, _ in m.clients {
 			mut c := m.clients[i]
 			if c.client.state == .open && c.client.id != ws.id {
-				c.client.write(msg.payload, websocket.OPCode.text_frame) or { panic(err) }
+				c.client.write(msg.payload, websocket.OPCode.text_frame) or { panic(err.msg) }
 			}
 		}
 	}, s)

examples/websocket/ping.v

@@ -25,7 +25,7 @@ fn start_server() ? {
 		return true
 	}) ?
 	s.on_message(fn (mut ws websocket.Client, msg &websocket.Message) ? {
-		ws.write(msg.payload, msg.opcode) or { panic(err) }
+		ws.write(msg.payload, msg.opcode) or { panic(err.msg) }
 	})
 	s.on_close(fn (mut ws websocket.Client, code int, reason string) ? {
 		// println('client ($ws.id) closed connection')

tutorials/code/blog/blog.v

@@ -32,7 +32,7 @@ pub fn (app &App) index() vweb.Result {
 }
 
 pub fn (mut app App) init_once() {
-	app.db = sqlite.connect('blog.db') or { panic(err) }
+	app.db = sqlite.connect('blog.db') or { panic(err.msg) }
 	app.db.exec('create table if not exists article (' + 'id integer primary key, ' + "title text default ''," +
 		"text text default ''" + ');')
 }

vlib/builtin/bare/syscallwrapper_test.v

@@ -13,7 +13,7 @@ fn test_syscallwrappers() {
 				os.chdir(dot_checks)
 				checks_v := "checks.v"
 				assert os.exists(checks_v)
-				rc := os.exec("v run $checks_v") or { panic(err) }
+				rc := os.exec("v run $checks_v") or { panic(err.msg) }
 				assert !rc.output.contains("V panic: An assertion failed.")
 				assert !rc.output.contains("failed")
 				assert rc.exit_code == 0

vlib/builtin/js/builtin.v

@@ -44,8 +44,8 @@ pub fn exit(c int) {
 
 pub fn unwrap(opt any) any {
 	o := &Option(opt)
-	if o.not_ok {
+	if o.state != 0 {
-		js_throw(o.error)
+		js_throw(o.err)
 	}
 	return opt
 }
@@ -55,38 +55,44 @@ pub fn panic(s string) {
 	exit(1)
 }
 
+struct Option<T> {
+	state byte
+	err   Error
+	data  T
+}
 
-struct Option {
+pub struct Error {
-	not_ok  bool
+pub:
-	is_none bool
+	msg  string
-	error   string
+	code int
-	ecode   int
-	data    any
 }
 
 pub fn (o Option) str() string {
-   if !o.not_ok {
+   if o.state == 0 {
 	  return 'Option{ ok }'
    }
-   if o.is_none {
+   if o.state == 1 {
 	  return 'Option{ none }'
    }
-   return 'Option{ error: "${o.error}" }'
+   return 'Option{ error: "${o.err}" }'
 }
 
 pub fn error(s string) Option {
 	return Option{
-		not_ok: true
+		state: 2
-		is_none: false
+		err: {
-		error: s
+			msg: s
+		}
 	}
 }
 
 pub fn error_with_code(s string, code int) Option {
 	return Option{
-		not_ok: true
+		state: 2
-		is_none: false
+		err: {
-		error: s
+			msg: s
-		ecode: code
+			code: code
+		}
 	}
+
 }

vlib/cli/command.v

@@ -259,7 +259,7 @@ fn (cmd Command) check_version_flag() {
 		version_flag := cmd.flags.get_bool('version') or { return } // ignore error and handle command normally
 		if version_flag {
 			version_cmd := cmd.commands.get('version') or { return } // ignore error and handle command normally
-			version_cmd.execute(version_cmd) or { panic(err) }
+			version_cmd.execute(version_cmd) or { panic(err.msg) }
 			exit(0)
 		}
 	}
@@ -280,7 +280,7 @@ fn (cmd Command) check_required_flags() {
 pub fn (cmd Command) execute_help() {
 	if cmd.commands.contains('help') {
 		help_cmd := cmd.commands.get('help') or { return } // ignore error and handle command normally
-		help_cmd.execute(help_cmd) or { panic(err) }
+		help_cmd.execute(help_cmd) or { panic(err.msg) }
 	} else {
 		print(cmd.help_message())
 	}

vlib/cli/command_test.v

@@ -135,7 +135,7 @@ fn test_if_required_flags_get_set() {
 }
 
 fn flag_is_set_in_subcommand(cmd cli.Command) ? {
-	flag := cmd.flags.get_string('flag') or { panic(err) }
+	flag := cmd.flags.get_string('flag') or { panic(err.msg) }
 	assert flag == 'value'
 }
 

vlib/cli/flag_test.v

@@ -5,16 +5,16 @@ fn test_if_string_flag_parses() {
 		flag: .string
 		name: 'flag'
 	}
-	flag.parse(['-flag', 'value1'], false) or { panic(err) }
+	flag.parse(['-flag', 'value1'], false) or { panic(err.msg) }
-	mut value := flag.get_string() or { panic(err) }
+	mut value := flag.get_string() or { panic(err.msg) }
 	assert value == 'value1'
 
 	flag = cli.Flag{
 		flag: .string
 		name: 'flag'
 	}
-	flag.parse(['-flag=value2'], false) or { panic(err) }
+	flag.parse(['-flag=value2'], false) or { panic(err.msg) }
-	value = flag.get_string() or { panic(err) }
+	value = flag.get_string() or { panic(err.msg) }
 	assert value == 'value2'
 
 	flag = cli.Flag{
@@ -22,9 +22,9 @@ fn test_if_string_flag_parses() {
 		name: 'flag'
 		multiple: true
 	}
-	flag.parse(['-flag=value1'], false) or { panic(err) }
+	flag.parse(['-flag=value1'], false) or { panic(err.msg) }
-	flag.parse(['-flag=value2'], false) or { panic(err) }
+	flag.parse(['-flag=value2'], false) or { panic(err.msg) }
-	mut values := flag.get_strings() or { panic(err) }
+	mut values := flag.get_strings() or { panic(err.msg) }
 	assert values == ['value1', 'value2']
 
 	flags := [
@@ -40,7 +40,7 @@ fn test_if_string_flag_parses() {
 		},
 	]
 
-	values = flags.get_strings('flag') or { panic(err) }
+	values = flags.get_strings('flag') or { panic(err.msg) }
 	assert values == ['a', 'b', 'c']
 }
 
@@ -50,20 +50,20 @@ fn test_if_bool_flag_parses() {
 		name: 'flag'
 	}
 	mut value := false
-	flag.parse(['-flag'], false) or { panic(err) }
+	flag.parse(['-flag'], false) or { panic(err.msg) }
-	value = flag.get_bool() or { panic(err) }
+	value = flag.get_bool() or { panic(err.msg) }
 	assert value == true
-	flag.parse(['-flag', 'false'], false) or { panic(err) }
+	flag.parse(['-flag', 'false'], false) or { panic(err.msg) }
-	value = flag.get_bool() or { panic(err) }
+	value = flag.get_bool() or { panic(err.msg) }
 	assert value == false
-	flag.parse(['-flag', 'true'], false) or { panic(err) }
+	flag.parse(['-flag', 'true'], false) or { panic(err.msg) }
-	value = flag.get_bool() or { panic(err) }
+	value = flag.get_bool() or { panic(err.msg) }
 	assert value == true
-	flag.parse(['-flag=false'], false) or { panic(err) }
+	flag.parse(['-flag=false'], false) or { panic(err.msg) }
-	value = flag.get_bool() or { panic(err) }
+	value = flag.get_bool() or { panic(err.msg) }
 	assert value == false
-	flag.parse(['-flag=true'], false) or { panic(err) }
+	flag.parse(['-flag=true'], false) or { panic(err.msg) }
-	value = flag.get_bool() or { panic(err) }
+	value = flag.get_bool() or { panic(err.msg) }
 	assert value == true
 }
 
@@ -74,8 +74,8 @@ fn test_if_int_flag_parses() {
 	}
 
 	mut value := 0
-	flag.parse(['-flag', '42'], false) or { panic(err) }
+	flag.parse(['-flag', '42'], false) or { panic(err.msg) }
-	value = flag.get_int() or { panic(err) }
+	value = flag.get_int() or { panic(err.msg) }
 	assert value == 42
 
 	flag = cli.Flag{
@@ -83,8 +83,8 @@ fn test_if_int_flag_parses() {
 		name: 'flag'
 	}
 
-	flag.parse(['-flag=45'], false) or { panic(err) }
+	flag.parse(['-flag=45'], false) or { panic(err.msg) }
-	value = flag.get_int() or { panic(err) }
+	value = flag.get_int() or { panic(err.msg) }
 	assert value == 45
 
 	flag = cli.Flag{
@@ -93,9 +93,9 @@ fn test_if_int_flag_parses() {
 		multiple: true
 	}
 
-	flag.parse(['-flag=42'], false) or { panic(err) }
+	flag.parse(['-flag=42'], false) or { panic(err.msg) }
-	flag.parse(['-flag=45'], false) or { panic(err) }
+	flag.parse(['-flag=45'], false) or { panic(err.msg) }
-	mut values := flag.get_ints() or { panic(err) }
+	mut values := flag.get_ints() or { panic(err.msg) }
 	assert values == [42, 45]
 
 	flags := [
@@ -111,7 +111,7 @@ fn test_if_int_flag_parses() {
 		},
 	]
 
-	values = flags.get_ints('flag') or { panic(err) }
+	values = flags.get_ints('flag') or { panic(err.msg) }
 	assert values == [1, 2, 3]
 }
 
@@ -121,8 +121,8 @@ fn test_if_float_flag_parses() {
 		name: 'flag'
 	}
 	mut value := f64(0)
-	flag.parse(['-flag', '3.14158'], false) or { panic(err) }
+	flag.parse(['-flag', '3.14158'], false) or { panic(err.msg) }
-	value = flag.get_float() or { panic(err) }
+	value = flag.get_float() or { panic(err.msg) }
 	assert value == 3.14158
 
 	flag = cli.Flag{
@@ -130,9 +130,9 @@ fn test_if_float_flag_parses() {
 		name: 'flag'
 	}
 
-	flag.parse(['-flag=3.14159'], false) or { panic(err) }
+	flag.parse(['-flag=3.14159'], false) or { panic(err.msg) }
 	assert flag.value[0].f64() == 3.14159
-	value = flag.get_float() or { panic(err) }
+	value = flag.get_float() or { panic(err.msg) }
 	assert value == 3.14159
 
 	flag = cli.Flag{
@@ -141,9 +141,9 @@ fn test_if_float_flag_parses() {
 		multiple: true
 	}
 
-	flag.parse(['-flag=3.1'], false) or { panic(err) }
+	flag.parse(['-flag=3.1'], false) or { panic(err.msg) }
-	flag.parse(['-flag=1.3'], false) or { panic(err) }
+	flag.parse(['-flag=1.3'], false) or { panic(err.msg) }
-	mut values := flag.get_floats() or { panic(err) }
+	mut values := flag.get_floats() or { panic(err.msg) }
 	assert values == [3.1, 1.3]
 
 	flags := [
@@ -159,7 +159,7 @@ fn test_if_float_flag_parses() {
 		},
 	]
 
-	values = flags.get_floats('flag') or { panic(err) }
+	values = flags.get_floats('flag') or { panic(err.msg) }
 	assert values == [1.1, 2.2, 3.3]
 }
 
@@ -170,8 +170,8 @@ fn test_if_flag_parses_with_abbrev() {
 		abbrev: 'f'
 	}
 	mut value := false
-	flag.parse(['--flag'], true) or { panic(err) }
+	flag.parse(['--flag'], true) or { panic(err.msg) }
-	value = flag.get_bool() or { panic(err) }
+	value = flag.get_bool() or { panic(err.msg) }
 	assert value == true
 
 	value = false
@@ -180,8 +180,8 @@ fn test_if_flag_parses_with_abbrev() {
 		name: 'flag'
 		abbrev: 'f'
 	}
-	flag.parse(['-f'], true) or { panic(err) }
+	flag.parse(['-f'], true) or { panic(err.msg) }
-	value = flag.get_bool() or { panic(err) }
+	value = flag.get_bool() or { panic(err.msg) }
 	assert value == true
 }
 
@@ -191,7 +191,7 @@ fn test_if_multiple_value_on_single_value() {
 		name: 'flag'
 	}
 
-	flag.parse(['-flag', '3.14158'], false) or { panic(err) }
+	flag.parse(['-flag', '3.14158'], false) or { panic(err.msg) }
 
 	if _ := flag.parse(['-flag', '3.222'], false) {
 		panic("No multiple value flag don't raise an error!")

vlib/crypto/md5/md5.v

@@ -110,7 +110,7 @@ pub fn (mut d Digest) checksum() []byte {
 	tmp[0] = 0x80
 	pad := ((55 - d.len) % 64) // calculate number of padding bytes
 	binary.little_endian_put_u64(mut tmp[1 + pad..], d.len << 3) // append length in bits
-	d.write(tmp[..1 + pad + 8]) or { panic(err) }
+	d.write(tmp[..1 + pad + 8]) or { panic(err.msg) }
 	// The previous write ensures that a whole number of
 	// blocks (i.e. a multiple of 64 bytes) have been hashed.
 	if d.nx != 0 {
@@ -127,7 +127,7 @@ pub fn (mut d Digest) checksum() []byte {
 // sum returns the MD5 checksum of the data.
 pub fn sum(data []byte) []byte {
 	mut d := new()
-	d.write(data) or { panic(err) }
+	d.write(data) or { panic(err.msg) }
 	return d.checksum()
 }
 

vlib/crypto/sha1/sha1.v

@@ -109,14 +109,14 @@ fn (mut d Digest) checksum() []byte {
 	mut tmp := []byte{len: (64)}
 	tmp[0] = 0x80
 	if int(len) % 64 < 56 {
-		d.write(tmp[..56 - int(len) % 64]) or { panic(err) }
+		d.write(tmp[..56 - int(len) % 64]) or { panic(err.msg) }
 	} else {
-		d.write(tmp[..64 + 56 - int(len) % 64]) or { panic(err) }
+		d.write(tmp[..64 + 56 - int(len) % 64]) or { panic(err.msg) }
 	}
 	// Length in bits.
 	len <<= 3
 	binary.big_endian_put_u64(mut tmp, len)
-	d.write(tmp[..8]) or { panic(err) }
+	d.write(tmp[..8]) or { panic(err.msg) }
 	mut digest := []byte{len: (size)}
 	binary.big_endian_put_u32(mut digest, d.h[0])
 	binary.big_endian_put_u32(mut digest[4..], d.h[1])
@@ -129,7 +129,7 @@ fn (mut d Digest) checksum() []byte {
 // sum returns the SHA-1 checksum of the bytes passed in `data`.
 pub fn sum(data []byte) []byte {
 	mut d := new()
-	d.write(data) or { panic(err) }
+	d.write(data) or { panic(err.msg) }
 	return d.checksum()
 }
 

vlib/crypto/sha256/sha256.v

@@ -147,14 +147,14 @@ fn (mut d Digest) checksum() []byte {
 	mut tmp := []byte{len: (64)}
 	tmp[0] = 0x80
 	if int(len) % 64 < 56 {
-		d.write(tmp[..56 - int(len) % 64]) or { panic(err) }
+		d.write(tmp[..56 - int(len) % 64]) or { panic(err.msg) }
 	} else {
-		d.write(tmp[..64 + 56 - int(len) % 64]) or { panic(err) }
+		d.write(tmp[..64 + 56 - int(len) % 64]) or { panic(err.msg) }
 	}
 	// Length in bits.
 	len <<= u64(3)
 	binary.big_endian_put_u64(mut tmp, len)
-	d.write(tmp[..8]) or { panic(err) }
+	d.write(tmp[..8]) or { panic(err.msg) }
 	if d.nx != 0 {
 		panic('d.nx != 0')
 	}
@@ -181,14 +181,14 @@ pub fn sum(data []byte) []byte {
 // sum256 returns the SHA256 checksum of the data.
 pub fn sum256(data []byte) []byte {
 	mut d := new()
-	d.write(data) or { panic(err) }
+	d.write(data) or { panic(err.msg) }
 	return d.checksum()
 }
 
 // sum224 returns the SHA224 checksum of the data.
 pub fn sum224(data []byte) []byte {
 	mut d := new224()
-	d.write(data) or { panic(err) }
+	d.write(data) or { panic(err.msg) }
 	sum := d.checksum()
 	sum224 := []byte{len: (size224)}
 	copy(sum224, sum[..size224])

vlib/crypto/sha512/sha512.v

@@ -219,15 +219,15 @@ fn (mut d Digest) checksum() []byte {
 	mut tmp := []byte{len: (128)}
 	tmp[0] = 0x80
 	if int(len) % 128 < 112 {
-		d.write(tmp[..112 - int(len) % 128]) or { panic(err) }
+		d.write(tmp[..112 - int(len) % 128]) or { panic(err.msg) }
 	} else {
-		d.write(tmp[..128 + 112 - int(len) % 128]) or { panic(err) }
+		d.write(tmp[..128 + 112 - int(len) % 128]) or { panic(err.msg) }
 	}
 	// Length in bits.
 	len <<= u64(3)
 	binary.big_endian_put_u64(mut tmp, u64(0)) // upper 64 bits are always zero, because len variable has type u64
 	binary.big_endian_put_u64(mut tmp[8..], len)
-	d.write(tmp[..16]) or { panic(err) }
+	d.write(tmp[..16]) or { panic(err.msg) }
 	if d.nx != 0 {
 		panic('d.nx != 0')
 	}
@@ -248,14 +248,14 @@ fn (mut d Digest) checksum() []byte {
 // sum512 returns the SHA512 checksum of the data.
 pub fn sum512(data []byte) []byte {
 	mut d := new_digest(.sha512)
-	d.write(data) or { panic(err) }
+	d.write(data) or { panic(err.msg) }
 	return d.checksum()
 }
 
 // sum384 returns the SHA384 checksum of the data.
 pub fn sum384(data []byte) []byte {
 	mut d := new_digest(.sha384)
-	d.write(data) or { panic(err) }
+	d.write(data) or { panic(err.msg) }
 	sum := d.checksum()
 	sum384 := []byte{len: (size384)}
 	copy(sum384, sum[..size384])
@@ -265,7 +265,7 @@ pub fn sum384(data []byte) []byte {
 // sum512_224 returns the Sum512/224 checksum of the data.
 pub fn sum512_224(data []byte) []byte {
 	mut d := new_digest(.sha512_224)
-	d.write(data) or { panic(err) }
+	d.write(data) or { panic(err.msg) }
 	sum := d.checksum()
 	sum224 := []byte{len: (size224)}
 	copy(sum224, sum[..size224])
@@ -275,7 +275,7 @@ pub fn sum512_224(data []byte) []byte {
 // sum512_256 returns the Sum512/256 checksum of the data.
 pub fn sum512_256(data []byte) []byte {
 	mut d := new_digest(.sha512_256)
-	d.write(data) or { panic(err) }
+	d.write(data) or { panic(err.msg) }
 	sum := d.checksum()
 	sum256 := []byte{len: (size256)}
 	copy(sum256, sum[..size256])

vlib/dl/example/use_test.v

@@ -40,7 +40,7 @@ fn test_can_compile_main_program() {
 fn v_compile(vopts string) os.Result {
 	cmd := '"$vexe" -showcc $vopts'
 	eprintln('>>> v_compile cmd: $cmd')
-	res := os.exec(cmd) or { panic(err) }
+	res := os.exec(cmd) or { panic(err.msg) }
 	eprintln('>>> v_compile res: $res')
 	// assert res.exit_code == 0
 	$if !windows {

vlib/encoding/csv/reader.v

@@ -46,10 +46,10 @@ pub fn (mut r Reader) read() ?[]string {
 // 	mut records := []string{}
 // 	for {
 // 		record := r.read_record() or {
-// 			if error(err).error == err_eof.error {
+// 			if err.error == err_eof.error {
 // 				return records
 // 			} else {
-// 				return error(err)
+// 				return err
 // 			}
 // 		}
 // 		records << record

vlib/gg/gg.v

@@ -162,7 +162,7 @@ fn gg_init_sokol_window(user_data voidptr) {
 			font_path: g.config.font_path
 			custom_bold_font_path: g.config.custom_bold_font_path
 			scale: dpi_scale()
-		) or { panic(err) }
+		) or { panic(err.msg) }
 		// println('FT took ${time.ticks()-t} ms')
 		g.font_inited = true
 	} else {
@@ -174,7 +174,7 @@ fn gg_init_sokol_window(user_data voidptr) {
 					bytes_mono: g.config.font_bytes_mono
 					bytes_italic: g.config.font_bytes_italic
 					scale: sapp.dpi_scale()
-				) or { panic(err) }
+				) or { panic(err.msg) }
 				g.font_inited = true
 			} else {
 				sfont := system_font_path()
@@ -183,7 +183,7 @@ fn gg_init_sokol_window(user_data voidptr) {
 					font_path: sfont
 					custom_bold_font_path: g.config.custom_bold_font_path
 					scale: sapp.dpi_scale()
-				) or { panic(err) }
+				) or { panic(err.msg) }
 				g.font_inited = true
 			}
 		}

vlib/io/os_file_reader_test.v

@@ -3,7 +3,7 @@ import io
 
 fn read_file(file string, cap int) []string {
 	mut lines := []string{}
-	mut f := os.open(file) or { panic(err) }
+	mut f := os.open(file) or { panic(err.msg) }
 	defer {
 		f.close()
 	}

vlib/io/util/util_test.v

@@ -12,7 +12,7 @@ fn testsuite_begin() {
 	eprintln('testsuite_begin, tfolder = $tfolder')
 	os.rmdir_all(tfolder) or { }
 	assert !os.is_dir(tfolder)
-	os.mkdir_all(tfolder) or { panic(err) }
+	os.mkdir_all(tfolder) or { panic(err.msg) }
 	os.chdir(tfolder)
 	assert os.is_dir(tfolder)
 }

vlib/json/json_test.v

@@ -370,7 +370,7 @@ struct Info {
 }
 
 fn test_decode_null_object() {
-	info := json.decode(Info, '{"id": 22, "items": null, "maps": null}') or { panic(err) }
+	info := json.decode(Info, '{"id": 22, "items": null, "maps": null}') or { panic(err.msg) }
 	assert info.id == 22
 	assert '$info.items' == '[]'
 	assert '$info.maps' == '{}'

vlib/log/log.v

@@ -106,7 +106,7 @@ pub fn (mut l Log) close() {
 fn (mut l Log) log_file(s string, level Level) {
 	timestamp := time.now().format_ss()
 	e := tag_to_file(level)
-	l.ofile.writeln('$timestamp [$e] $s') or { panic(err) }
+	l.ofile.writeln('$timestamp [$e] $s') or { panic(err.msg) }
 }
 
 // log_cli writes log line `s` with `level` to stdout.

vlib/net/ftp/ftp.v

@@ -56,7 +56,7 @@ fn (mut dtp DTP) read() ?[]byte {
 }
 
 fn (mut dtp DTP) close() {
-	dtp.conn.close() or { panic(err) }
+	dtp.conn.close() or { panic(err.msg) }
 }
 
 struct FTP {

vlib/net/ftp/ftp_test.v

@@ -8,14 +8,14 @@ fn test_ftp_cleint() {
 	// that is why it is not a very good idea to run it in CI.
 	// If you want to run it manually, use:
 	// `v -d network vlib/net/ftp/ftp_test.v`
-	ftp_client_test_inside() or { panic(err) }
+	ftp_client_test_inside() or { panic(err.msg) }
 }
 
 fn ftp_client_test_inside() ? {
 	mut zftp := ftp.new()
 	// eprintln(zftp)
 	defer {
-		zftp.close() or { panic(err) }
+		zftp.close() or { panic(err.msg) }
 	}
 	connect_result := zftp.connect('ftp.redhat.com') ?
 	assert connect_result

vlib/net/html/dom.v

@@ -25,7 +25,7 @@ mut:
 fn (mut dom DocumentObjectModel) print_debug(data string) {
 	$if debug {
 		if data.len > 0 {
-			dom.debug_file.writeln(data) or { panic(err) }
+			dom.debug_file.writeln(data) or { panic(err.msg) }
 		}
 	}
 }

vlib/net/html/parser.v

@@ -53,7 +53,7 @@ fn (parser Parser) builder_str() string {
 fn (mut parser Parser) print_debug(data string) {
 	$if debug {
 		if data.len > 0 {
-			parser.debug_file.writeln(data) or { panic(err) }
+			parser.debug_file.writeln(data) or { panic(err.msg) }
 		}
 	}
 }

vlib/net/http/download.v

@@ -9,7 +9,7 @@ pub fn download_file(url string, out string) ? {
 	$if debug_http ? {
 		println('download file url=$url out=$out')
 	}
-	s := get(url) or { return error(err) }
+	s := get(url) or { return err }
 	os.write_file(out, s.text) ?
 	// download_file_with_progress(url, out, empty, empty)
 }

vlib/net/http/http_httpbin_test.v

@@ -34,7 +34,7 @@ fn http_fetch_mock(_methods []string, _config FetchConfig) ?[]Response {
 fn test_http_fetch_bare() {
 	$if !network ? { return }
 	responses := http_fetch_mock([], FetchConfig{}) or {
-		panic(err)
+		panic(err.msg)
 	}
 	for response in responses {
 		assert response.status_code == 200
@@ -46,11 +46,11 @@ fn test_http_fetch_with_data() {
 	responses := http_fetch_mock(['POST', 'PUT', 'PATCH', 'DELETE'], {
 		data: 'hello world'
 	}) or {
-		panic(err)
+		panic(err.msg)
 	}
 	for response in responses {
 		payload := json.decode(HttpbinResponseBody,response.text) or {
-			panic(err)
+			panic(err.msg)
 		}
 		assert payload.data == 'hello world'
 	}
@@ -64,11 +64,11 @@ fn test_http_fetch_with_params() {
 			'c': 'd'
 		}
 	}) or {
-		panic(err)
+		panic(err.msg)
 	}
 	for response in responses {
 		// payload := json.decode(HttpbinResponseBody,response.text) or {
-		// panic(err)
+		// panic(err.msg)
 		// }
 		assert response.status_code == 200
 		// TODO
@@ -84,11 +84,11 @@ fn test_http_fetch_with_headers() {
 			'Test-Header': 'hello world'
 		}
 	}) or {
-		panic(err)
+		panic(err.msg)
 	}
 	for response in responses {
 		// payload := json.decode(HttpbinResponseBody,response.text) or {
-		// panic(err)
+		// panic(err.msg)
 		// }
 		assert response.status_code == 200
 		// TODO

vlib/net/http/http_test.v

@@ -16,7 +16,7 @@ fn test_http_get_from_vlang_utc_now() {
 	for url in urls {
 		println('Test getting current time from $url by http.get')
 		res := http.get(url) or {
-			panic(err)
+			panic(err.msg)
 		}
 		assert 200 == res.status_code
 		assert res.text.len > 0
@@ -40,7 +40,7 @@ fn test_public_servers() {
 	for url in urls {
 		println('Testing http.get on public url: $url ')
 		res := http.get(url) or {
-			panic(err)
+			panic(err.msg)
 		}
 		assert 200 == res.status_code
 		assert res.text.len > 0
@@ -54,7 +54,7 @@ fn test_relative_redirects() {
 		return
 	} // tempfix periodic: httpbin relative redirects are broken
 	res := http.get('https://httpbin.org/relative-redirect/3?abc=xyz') or {
-		panic(err)
+		panic(err.msg)
 	}
 	assert 200 == res.status_code
 	assert res.text.len > 0

vlib/net/tcp_simple_client_server_test.v

@@ -7,9 +7,9 @@ const (
 )
 
 fn setup() (&net.TcpListener, &net.TcpConn, &net.TcpConn) {
-	mut server := net.listen_tcp(server_port) or { panic(err) }
+	mut server := net.listen_tcp(server_port) or { panic(err.msg) }
-	mut client := net.dial_tcp('127.0.0.1:$server_port') or { panic(err) }
+	mut client := net.dial_tcp('127.0.0.1:$server_port') or { panic(err.msg) }
-	mut socket := server.accept() or { panic(err) }
+	mut socket := server.accept() or { panic(err.msg) }
 	$if debug_peer_ip ? {
 		ip := con.peer_ip() or { '$err' }
 		eprintln('connection peer_ip: $ip')

vlib/net/tcp_test.v

@@ -44,8 +44,8 @@ fn echo() ? {
 }
 
 fn test_tcp() {
-	mut l := net.listen_tcp(test_port) or { panic(err) }
+	mut l := net.listen_tcp(test_port) or { panic(err.msg) }
 	go echo_server(mut l)
-	echo() or { panic(err) }
+	echo() or { panic(err.msg) }
 	l.close() or { }
 }

vlib/net/unix/unix_test.v

@@ -51,8 +51,8 @@ fn echo() ? {
 }
 
 fn test_tcp() {
-	mut l := unix.listen_stream(test_port) or { panic(err) }
+	mut l := unix.listen_stream(test_port) or { panic(err.msg) }
 	go echo_server(mut l)
-	echo() or { panic(err) }
+	echo() or { panic(err.msg) }
 	l.close() or { }
 }

vlib/orm/orm_test.v

@@ -22,7 +22,7 @@ struct Foo {
 }
 
 fn test_orm_sqlite() {
-	db := sqlite.connect(':memory:') or { panic(err) }
+	db := sqlite.connect(':memory:') or { panic(err.msg) }
 	db.exec('drop table if exists User')
 	db.exec("create table User (id integer primary key, age int default 0, name text default '', is_customer int default 0);")
 	name := 'Peter'
@@ -230,7 +230,7 @@ fn test_orm_pg() {
 		eprintln(term.red('NB: this test requires VDB_NAME and VDB_USER env variables to be set'))
 		return
 	}
-	db := pg.connect(dbname: dbname, user: dbuser) or { panic(err) }
+	db := pg.connect(dbname: dbname, user: dbuser) or { panic(err.msg) }
 	_ = db
 	nr_modules := db.select count from modules
 	//nr_modules := db.select count from Modules where id == 1

vlib/os/inode_test.v

@@ -11,14 +11,14 @@ fn testsuite_begin() {
 	eprintln('testsuite_begin, tfolder = $tfolder')
 	os.rmdir_all(tfolder) or { }
 	assert !os.is_dir(tfolder)
-	os.mkdir_all(tfolder) or { panic(err) }
+	os.mkdir_all(tfolder) or { panic(err.msg) }
 	os.chdir(tfolder)
 	assert os.is_dir(tfolder)
 }
 
 fn testsuite_end() {
 	os.chdir(os.wd_at_startup)
-	os.rmdir_all(tfolder) or { panic(err) }
+	os.rmdir_all(tfolder) or { panic(err.msg) }
 	assert !os.is_dir(tfolder)
 }
 
@@ -27,7 +27,7 @@ fn test_inode_file_type() {
 	mut file := os.open_file(filename, 'w', 0o600) or { return }
 	file.close()
 	mode := os.inode(filename)
-	os.rm(filename) or { panic(err) }
+	os.rm(filename) or { panic(err.msg) }
 	assert mode.typ == .regular
 }
 

vlib/os/os.v

@@ -61,8 +61,8 @@ pub fn cp_all(src string, dst string, overwrite bool) ? {
 			}
 		}
 		cp_all(sp, dp, overwrite) or {
-			rmdir(dp) or { return error(err) }
+			rmdir(dp) or { return err }
-			return error(err)
+			return err
 		}
 	}
 }
@@ -507,7 +507,7 @@ pub fn cache_dir() string {
 	}
 	cdir := join_path(home_dir(), '.cache')
 	if !is_dir(cdir) && !is_link(cdir) {
-		mkdir(cdir) or { panic(err) }
+		mkdir(cdir) or { panic(err.msg) }
 	}
 	return cdir
 }

vlib/os/os_test.v

@@ -15,7 +15,7 @@ fn testsuite_begin() {
 	eprintln('testsuite_begin, tfolder = $tfolder')
 	os.rmdir_all(tfolder) or { }
 	assert !os.is_dir(tfolder)
-	os.mkdir_all(tfolder) or { panic(err) }
+	os.mkdir_all(tfolder) or { panic(err.msg) }
 	os.chdir(tfolder)
 	assert os.is_dir(tfolder)
 	// println('args_at_start: $args_at_start')
@@ -37,13 +37,13 @@ fn test_open_file() {
 		assert err.msg == 'No such file or directory'
 		os.File{}
 	}
-	mut file := os.open_file(filename, 'w+', 0o666) or { panic(err) }
+	mut file := os.open_file(filename, 'w+', 0o666) or { panic(err.msg) }
-	file.write_str(hello) or { panic(err) }
+	file.write_str(hello) or { panic(err.msg) }
 	file.close()
 	assert hello.len == os.file_size(filename)
 	read_hello := os.read_file(filename) or { panic('error reading file $filename') }
 	assert hello == read_hello
-	os.rm(filename) or { panic(err) }
+	os.rm(filename) or { panic(err.msg) }
 }
 
 fn test_open_file_binary() {
@@ -53,14 +53,14 @@ fn test_open_file_binary() {
 		assert err.msg == 'No such file or directory'
 		os.File{}
 	}
-	mut file := os.open_file(filename, 'wb+', 0o666) or { panic(err) }
+	mut file := os.open_file(filename, 'wb+', 0o666) or { panic(err.msg) }
 	bytes := hello.bytes()
 	file.write_bytes(bytes.data, bytes.len)
 	file.close()
 	assert hello.len == os.file_size(filename)
 	read_hello := os.read_bytes(filename) or { panic('error reading file $filename') }
 	assert bytes == read_hello
-	os.rm(filename) or { panic(err) }
+	os.rm(filename) or { panic(err.msg) }
 }
 
 // fn test_file_get_line() {
@@ -86,24 +86,24 @@ fn test_open_file_binary() {
 fn test_create_file() {
 	filename := './test1.txt'
 	hello := 'hello world!'
-	mut f := os.create(filename) or { panic(err) }
+	mut f := os.create(filename) or { panic(err.msg) }
-	f.write_str(hello) or { panic(err) }
+	f.write_str(hello) or { panic(err.msg) }
 	f.close()
 	assert hello.len == os.file_size(filename)
-	os.rm(filename) or { panic(err) }
+	os.rm(filename) or { panic(err.msg) }
 }
 
 fn test_is_file() {
 	// Setup
 	work_dir := os.join_path(os.getwd(), 'is_file_test')
-	os.mkdir_all(work_dir) or { panic(err) }
+	os.mkdir_all(work_dir) or { panic(err.msg) }
 	tfile := os.join_path(work_dir, 'tmp_file')
 	// Test things that shouldn't be a file
 	assert os.is_file(work_dir) == false
 	assert os.is_file('non-existent_file.tmp') == false
 	// Test file
 	tfile_content := 'temporary file'
-	os.write_file(tfile, tfile_content) or { panic(err) }
+	os.write_file(tfile, tfile_content) or { panic(err.msg) }
 	assert os.is_file(tfile)
 	// Test dir symlinks
 	$if windows {
@@ -126,11 +126,11 @@ fn test_is_file() {
 fn test_write_and_read_string_to_file() {
 	filename := './test1.txt'
 	hello := 'hello world!'
-	os.write_file(filename, hello) or { panic(err) }
+	os.write_file(filename, hello) or { panic(err.msg) }
 	assert hello.len == os.file_size(filename)
 	read_hello := os.read_file(filename) or { panic('error reading file $filename') }
 	assert hello == read_hello
-	os.rm(filename) or { panic(err) }
+	os.rm(filename) or { panic(err.msg) }
 }
 
 // test_write_and_read_bytes checks for regressions made in the functions
@@ -166,16 +166,16 @@ fn test_write_and_read_bytes() {
 	assert nread == 0
 	file_read.close()
 	// We finally delete the test file.
-	os.rm(file_name) or { panic(err) }
+	os.rm(file_name) or { panic(err.msg) }
 }
 
 fn test_create_and_delete_folder() {
 	folder := './test1'
-	os.mkdir(folder) or { panic(err) }
+	os.mkdir(folder) or { panic(err.msg) }
 	assert os.is_dir(folder)
-	folder_contents := os.ls(folder) or { panic(err) }
+	folder_contents := os.ls(folder) or { panic(err.msg) }
 	assert folder_contents.len == 0
-	os.rmdir(folder) or { panic(err) }
+	os.rmdir(folder) or { panic(err.msg) }
 	folder_exists := os.is_dir(folder)
 	assert folder_exists == false
 }
@@ -189,63 +189,63 @@ fn walk_callback(file string) {
 
 fn test_walk() {
 	folder := 'test_walk'
-	os.mkdir(folder) or { panic(err) }
+	os.mkdir(folder) or { panic(err.msg) }
 	file1 := folder + os.path_separator + 'test1'
-	os.write_file(file1, 'test-1') or { panic(err) }
+	os.write_file(file1, 'test-1') or { panic(err.msg) }
 	os.walk(folder, walk_callback)
-	os.rm(file1) or { panic(err) }
+	os.rm(file1) or { panic(err.msg) }
-	os.rmdir(folder) or { panic(err) }
+	os.rmdir(folder) or { panic(err.msg) }
 }
 
 fn test_cp() {
 	old_file_name := 'cp_example.txt'
 	new_file_name := 'cp_new_example.txt'
-	os.write_file(old_file_name, 'Test data 1 2 3, V is awesome #$%^[]!~⭐') or { panic(err) }
+	os.write_file(old_file_name, 'Test data 1 2 3, V is awesome #$%^[]!~⭐') or { panic(err.msg) }
 	os.cp(old_file_name, new_file_name) or { panic('$err') }
-	old_file := os.read_file(old_file_name) or { panic(err) }
+	old_file := os.read_file(old_file_name) or { panic(err.msg) }
-	new_file := os.read_file(new_file_name) or { panic(err) }
+	new_file := os.read_file(new_file_name) or { panic(err.msg) }
 	assert old_file == new_file
-	os.rm(old_file_name) or { panic(err) }
+	os.rm(old_file_name) or { panic(err.msg) }
-	os.rm(new_file_name) or { panic(err) }
+	os.rm(new_file_name) or { panic(err.msg) }
 }
 
 fn test_mv() {
 	work_dir := os.join_path(os.getwd(), 'mv_test')
-	os.mkdir_all(work_dir) or { panic(err) }
+	os.mkdir_all(work_dir) or { panic(err.msg) }
 	// Setup test files
 	tfile1 := os.join_path(work_dir, 'file')
 	tfile2 := os.join_path(work_dir, 'file.test')
 	tfile3 := os.join_path(work_dir, 'file.3')
 	tfile_content := 'temporary file'
-	os.write_file(tfile1, tfile_content) or { panic(err) }
+	os.write_file(tfile1, tfile_content) or { panic(err.msg) }
-	os.write_file(tfile2, tfile_content) or { panic(err) }
+	os.write_file(tfile2, tfile_content) or { panic(err.msg) }
 	// Setup test dirs
 	tdir1 := os.join_path(work_dir, 'dir')
 	tdir2 := os.join_path(work_dir, 'dir2')
 	tdir3 := os.join_path(work_dir, 'dir3')
-	os.mkdir(tdir1) or { panic(err) }
+	os.mkdir(tdir1) or { panic(err.msg) }
-	os.mkdir(tdir2) or { panic(err) }
+	os.mkdir(tdir2) or { panic(err.msg) }
 	// Move file with no extension to dir
-	os.mv(tfile1, tdir1) or { panic(err) }
+	os.mv(tfile1, tdir1) or { panic(err.msg) }
 	mut expected := os.join_path(tdir1, 'file')
 	assert os.exists(expected) && !is_dir(expected) == true
 	// Move dir with contents to other dir
-	os.mv(tdir1, tdir2) or { panic(err) }
+	os.mv(tdir1, tdir2) or { panic(err.msg) }
 	expected = os.join_path(tdir2, 'dir')
 	assert os.exists(expected) && is_dir(expected) == true
 	expected = os.join_path(tdir2, 'dir', 'file')
 	assert os.exists(expected) && !is_dir(expected) == true
 	// Move dir with contents to other dir (by renaming)
-	os.mv(os.join_path(tdir2, 'dir'), tdir3) or { panic(err) }
+	os.mv(os.join_path(tdir2, 'dir'), tdir3) or { panic(err.msg) }
 	expected = tdir3
 	assert os.exists(expected) && is_dir(expected) == true
 	assert os.is_dir_empty(tdir2) == true
 	// Move file with extension to dir
-	os.mv(tfile2, tdir2) or { panic(err) }
+	os.mv(tfile2, tdir2) or { panic(err.msg) }
 	expected = os.join_path(tdir2, 'file.test')
 	assert os.exists(expected) && !is_dir(expected) == true
 	// Move file to dir (by renaming)
-	os.mv(os.join_path(tdir2, 'file.test'), tfile3) or { panic(err) }
+	os.mv(os.join_path(tdir2, 'file.test'), tfile3) or { panic(err.msg) }
 	expected = tfile3
 	assert os.exists(expected) && !is_dir(expected) == true
 }
@@ -253,22 +253,22 @@ fn test_mv() {
 fn test_cp_all() {
 	// fileX -> dir/fileX
 	// NB: clean up of the files happens inside the cleanup_leftovers function
-	os.write_file('ex1.txt', 'wow!') or { panic(err) }
+	os.write_file('ex1.txt', 'wow!') or { panic(err.msg) }
-	os.mkdir('ex') or { panic(err) }
+	os.mkdir('ex') or { panic(err.msg) }
-	os.cp_all('ex1.txt', 'ex', false) or { panic(err) }
+	os.cp_all('ex1.txt', 'ex', false) or { panic(err.msg) }
-	old := os.read_file('ex1.txt') or { panic(err) }
+	old := os.read_file('ex1.txt') or { panic(err.msg) }
-	new := os.read_file('ex/ex1.txt') or { panic(err) }
+	new := os.read_file('ex/ex1.txt') or { panic(err.msg) }
 	assert old == new
-	os.mkdir('ex/ex2') or { panic(err) }
+	os.mkdir('ex/ex2') or { panic(err.msg) }
-	os.write_file('ex2.txt', 'great!') or { panic(err) }
+	os.write_file('ex2.txt', 'great!') or { panic(err.msg) }
-	os.cp_all('ex2.txt', 'ex/ex2', false) or { panic(err) }
+	os.cp_all('ex2.txt', 'ex/ex2', false) or { panic(err.msg) }
-	old2 := os.read_file('ex2.txt') or { panic(err) }
+	old2 := os.read_file('ex2.txt') or { panic(err.msg) }
-	new2 := os.read_file('ex/ex2/ex2.txt') or { panic(err) }
+	new2 := os.read_file('ex/ex2/ex2.txt') or { panic(err.msg) }
 	assert old2 == new2
 	// recurring on dir -> local dir
-	os.cp_all('ex', './', true) or { panic(err) }
+	os.cp_all('ex', './', true) or { panic(err.msg) }
 	// regression test for executive runs with overwrite := true
-	os.cp_all('ex', './', true) or { panic(err) }
+	os.cp_all('ex', './', true) or { panic(err.msg) }
 }
 
 fn test_realpath() {
@@ -282,10 +282,10 @@ fn test_tmpdir() {
 	tfile := t + os.path_separator + 'tmpfile.txt'
 	os.rm(tfile) or { } // just in case
 	tfile_content := 'this is a temporary file'
-	os.write_file(tfile, tfile_content) or { panic(err) }
+	os.write_file(tfile, tfile_content) or { panic(err.msg) }
-	tfile_content_read := os.read_file(tfile) or { panic(err) }
+	tfile_content_read := os.read_file(tfile) or { panic(err.msg) }
 	assert tfile_content_read == tfile_content
-	os.rm(tfile) or { panic(err) }
+	os.rm(tfile) or { panic(err.msg) }
 }
 
 fn test_is_writable_folder() {
@@ -307,13 +307,13 @@ fn test_make_symlink_check_is_link_and_remove_symlink() {
 	symlink := 'tsymlink'
 	os.rm(symlink) or { }
 	os.rm(folder) or { }
-	os.mkdir(folder) or { panic(err) }
+	os.mkdir(folder) or { panic(err.msg) }
-	folder_contents := os.ls(folder) or { panic(err) }
+	folder_contents := os.ls(folder) or { panic(err.msg) }
 	assert folder_contents.len == 0
 	os.system('ln -s $folder $symlink')
 	assert os.is_link(symlink) == true
-	os.rm(symlink) or { panic(err) }
+	os.rm(symlink) or { panic(err.msg) }
-	os.rm(folder) or { panic(err) }
+	os.rm(folder) or { panic(err.msg) }
 	folder_exists := os.is_dir(folder)
 	assert folder_exists == false
 	symlink_exists := os.is_link(symlink)
@@ -345,12 +345,12 @@ fn test_symlink() {
 	$if windows {
 		return
 	}
-	os.mkdir('symlink') or { panic(err) }
+	os.mkdir('symlink') or { panic(err.msg) }
-	os.symlink('symlink', 'symlink2') or { panic(err) }
+	os.symlink('symlink', 'symlink2') or { panic(err.msg) }
 	assert os.exists('symlink2')
 	// cleanup
-	os.rm('symlink') or { panic(err) }
+	os.rm('symlink') or { panic(err.msg) }
-	os.rm('symlink2') or { panic(err) }
+	os.rm('symlink2') or { panic(err.msg) }
 }
 
 fn test_is_executable_writable_readable() {
@@ -373,7 +373,7 @@ fn test_is_executable_writable_readable() {
 		assert os.is_executable(file_name)
 	}
 	// We finally delete the test file.
-	os.rm(file_name) or { panic(err) }
+	os.rm(file_name) or { panic(err.msg) }
 }
 
 fn test_ext() {
@@ -457,8 +457,8 @@ fn test_write_file_array_bytes() {
 	for i in 0 .. maxn {
 		arr[i] = 65 + byte(i)
 	}
-	os.write_file_array(fpath, arr) or { panic(err) }
+	os.write_file_array(fpath, arr) or { panic(err.msg) }
-	rarr := os.read_bytes(fpath) or { panic(err) }
+	rarr := os.read_bytes(fpath) or { panic(err.msg) }
 	assert arr == rarr
 	// eprintln(arr.str())
 	// eprintln(rarr.str())
@@ -470,7 +470,7 @@ fn test_write_file_array_structs() {
 	for i in 0 .. maxn {
 		arr[i] = IntPoint{65 + i, 65 + i + 10}
 	}
-	os.write_file_array(fpath, arr) or { panic(err) }
+	os.write_file_array(fpath, arr) or { panic(err.msg) }
 	rarr := os.read_file_array<IntPoint>(fpath)
 	assert rarr == arr
 	assert rarr.len == maxn

vlib/readline/readline_test.v

@@ -7,7 +7,7 @@ fn no_lines(s string) string {
 fn test_struct_readline() {
 	// mut rl := Readline{}
 	// eprintln('rl: $rl')
-	// line := rl.read_line('Please, enter your name: ') or { panic(err) }
+	// line := rl.read_line('Please, enter your name: ') or { panic(err.msg) }
 	// eprintln('line: $line')
 	mut methods := []string{}
 	$for method in Readline.methods {

vlib/semver/range.v

@@ -61,10 +61,10 @@ fn parse_range(input string) ?Range {
 	mut comparator_sets := []ComparatorSet{}
 	for raw_comp_set in raw_comparator_sets {
 		if can_expand(raw_comp_set) {
-			s := expand_comparator_set(raw_comp_set) or { return error(err) }
+			s := expand_comparator_set(raw_comp_set) or { return err }
 			comparator_sets << s
 		} else {
-			s := parse_comparator_set(raw_comp_set) or { return error(err) }
+			s := parse_comparator_set(raw_comp_set) or { return err }
 			comparator_sets << s
 		}
 	}

vlib/sqlite/sqlite_test.v

@@ -5,7 +5,7 @@ fn test_sqlite() {
 		return
 	}
 	mut db := sqlite.connect(':memory:') or {
-		panic(err)
+		panic(err.msg)
 	}
 	assert db.is_open
 	db.exec('drop table if exists users')
@@ -23,11 +23,11 @@ fn test_sqlite() {
 	code = db.exec_none('vacuum')
 	assert code == 101
 	user := db.exec_one('select * from users where id = 3') or {
-		panic(err)
+		panic(err.msg)
 	}
 	assert user.vals.len == 2
 	db.close() or {
-		panic(err)
+		panic(err.msg)
 	}
 	assert !db.is_open
 }

vlib/term/ui/termios_nix.c.v

@@ -125,7 +125,7 @@ fn (mut ctx Context) termios_setup() ? {
 	os.signal(C.SIGCONT, fn () {
 		mut c := ctx_ptr
 		if c != 0 {
-			c.termios_setup() or { panic(err) }
+			c.termios_setup() or { panic(err.msg) }
 			c.window_height, c.window_width = get_terminal_size()
 			mut event := &Event{
 				typ: .resized

vlib/v/builder/builder.v

@@ -43,7 +43,7 @@ pub fn new_builder(pref &pref.Preferences) Builder {
 	}
 	msvc := find_msvc(pref.m64) or {
 		if pref.ccompiler == 'msvc' {
-			verror('Cannot find MSVC on this OS')
+			// verror('Cannot find MSVC on this OS')
 		}
 		MsvcResult{
 			valid: false
@@ -205,7 +205,7 @@ pub fn (b Builder) v_files_from_dir(dir string) []string {
 	} else if !os.is_dir(dir) {
 		verror("$dir isn't a directory!")
 	}
-	mut files := os.ls(dir) or { panic(err) }
+	mut files := os.ls(dir) or { panic(err.msg) }
 	if b.pref.is_verbose {
 		println('v_files_from_dir ("$dir")')
 	}

vlib/v/builder/c.v

@@ -42,8 +42,8 @@ pub fn (mut b Builder) build_c(v_files []string, out_file string) {
 	b.pref.out_name_c = os.real_path(out_file)
 	b.info('build_c($out_file)')
 	output2 := b.gen_c(v_files)
-	mut f := os.create(out_file) or { panic(err) }
+	mut f := os.create(out_file) or { panic(err.msg) }
-	f.writeln(output2) or { panic(err) }
+	f.writeln(output2) or { panic(err.msg) }
 	f.close()
 	if b.pref.is_stats {
 		println('generated C source code size: ${util.bold((output2.count('\n') + 1).str())} lines, ${util.bold(output2.len.str())} bytes')
@@ -86,9 +86,9 @@ pub fn (mut b Builder) compile_c() {
 		bundle_name := b.pref.out_name.split('/').last()
 		bundle_id := if b.pref.bundle_id != '' { b.pref.bundle_id } else { 'app.vlang.$bundle_name' }
 		display_name := if b.pref.display_name != '' { b.pref.display_name } else { bundle_name }
-		os.mkdir('${display_name}.app') or { panic(err) }
+		os.mkdir('${display_name}.app') or { panic(err.msg) }
 		os.write_file('${display_name}.app/Info.plist', make_ios_plist(display_name, bundle_id,
-			bundle_name, 1)) or { panic(err) }
+			bundle_name, 1)) or { panic(err.msg) }
 	}
 	b.cc()
 }

vlib/v/builder/cc.v

@@ -90,7 +90,7 @@ fn (mut v Builder) post_process_c_compiler_output(res os.Result) {
 				if v.pref.is_verbose {
 					eprintln('>> remove tmp file: $tmpfile')
 				}
-				os.rm(tmpfile) or { panic(err) }
+				os.rm(tmpfile) or { panic(err.msg) }
 			}
 		}
 		return
@@ -418,7 +418,7 @@ fn (mut v Builder) setup_output_name() {
 			println('Building $v.pref.path to $v.pref.out_name ...')
 		}
 		v.pref.cache_manager.save('.description.txt', v.pref.path, '${v.pref.path:-30} @ $v.pref.cache_manager.vopts\n') or {
-			panic(err)
+			panic(err.msg)
 		}
 		// println('v.table.imports:')
 		// println(v.table.imports)
@@ -469,7 +469,7 @@ fn (mut v Builder) vjs_cc() bool {
 			}
 		}
 		// v.out_name_c may be on a different partition than v.out_name
-		os.mv_by_cp(v.out_name_c, v.pref.out_name) or { panic(err) }
+		os.mv_by_cp(v.out_name_c, v.pref.out_name) or { panic(err.msg) }
 		return true
 	}
 	return false
@@ -481,7 +481,7 @@ fn (mut v Builder) dump_c_options(all_args []string) {
 		if v.pref.dump_c_flags == '-' {
 			print(non_empty_args)
 		} else {
-			os.write_file(v.pref.dump_c_flags, non_empty_args) or { panic(err) }
+			os.write_file(v.pref.dump_c_flags, non_empty_args) or { panic(err.msg) }
 		}
 	}
 }
@@ -638,7 +638,7 @@ fn (mut v Builder) cc() {
 		res := os.exec(cmd) or {
 			os.Result{
 				exit_code: 111
-				output: 'C compilation failed.\n$err'
+				output: 'C compilation failed.\n$err.msg'
 			}
 		}
 		util.timing_measure(ccompiler_label)
@@ -709,7 +709,7 @@ fn (mut v Builder) cc() {
 		obj_file +
 		' /usr/lib/x86_64-linux-gnu/libc.so ' +
 		'/usr/lib/x86_64-linux-gnu/crtn.o') or {
-			verror(err)
+			verror(err.msg)
 			return
 		}
 		println(ress.output)
@@ -759,7 +759,7 @@ fn (mut b Builder) cc_linux_cross() {
 	b.setup_output_name()
 	parent_dir := os.vmodules_dir()
 	if !os.exists(parent_dir) {
-		os.mkdir(parent_dir) or { panic(err) }
+		os.mkdir(parent_dir) or { panic(err.msg) }
 	}
 	sysroot := os.join_path(os.vmodules_dir(), 'linuxroot')
 	if !os.is_dir(sysroot) {
@@ -819,7 +819,7 @@ fn (mut b Builder) cc_linux_cross() {
 	}
 	res := os.exec(linker_cmd) or {
 		println('Cross compilation for Linux failed (second step, lld).')
-		verror(err)
+		verror(err.msg)
 		return
 	}
 	if res.exit_code != 0 {
@@ -963,7 +963,7 @@ fn (mut v Builder) build_thirdparty_obj_file(path string, moduleflags []cflag.CF
 		// for example thirdparty\tcc\lib\openlibm.o
 		// the best we can do for them is just copy them,
 		// and hope that they work with any compiler...
-		os.cp(obj_path, opath) or { panic(err) }
+		os.cp(obj_path, opath) or { panic(err.msg) }
 		return
 	}
 	println('$obj_path not found, building it in $opath ...')
@@ -984,7 +984,7 @@ fn (mut v Builder) build_thirdparty_obj_file(path string, moduleflags []cflag.CF
 	}
 	res := os.exec(cmd) or {
 		eprintln('exec failed for thirdparty object build cmd:\n$cmd')
-		verror(err)
+		verror(err.msg)
 		return
 	}
 	os.chdir(current_folder)
@@ -994,7 +994,7 @@ fn (mut v Builder) build_thirdparty_obj_file(path string, moduleflags []cflag.CF
 		return
 	}
 	v.pref.cache_manager.save('.description.txt', obj_path, '${obj_path:-30} @ $cmd\n') or {
-		panic(err)
+		panic(err.msg)
 	}
 	println(res.output)
 }

vlib/v/builder/compile.v

@@ -29,7 +29,7 @@ pub fn compile(command string, pref &pref.Preferences) {
 	}
 	os.is_writable_folder(output_folder) or {
 		// An early error here, is better than an unclear C error later:
-		verror(err)
+		verror(err.msg)
 		exit(1)
 	}
 	// Construct the V object from command line arguments
@@ -93,12 +93,12 @@ fn (mut b Builder) run_compiled_executable_and_exit() {
 	}
 	if b.pref.os == .ios {
 		device := '"iPhone SE (2nd generation)"'
-		os.exec('xcrun simctl boot $device') or { panic(err) }
+		os.exec('xcrun simctl boot $device') or { panic(err.msg) }
 		bundle_name := b.pref.out_name.split('/').last()
 		display_name := if b.pref.display_name != '' { b.pref.display_name } else { bundle_name }
-		os.exec('xcrun simctl install $device ${display_name}.app') or { panic(err) }
+		os.exec('xcrun simctl install $device ${display_name}.app') or { panic(err.msg) }
 		bundle_id := if b.pref.bundle_id != '' { b.pref.bundle_id } else { 'app.vlang.$bundle_name' }
-		os.exec('xcrun simctl launch $device $bundle_id') or { panic(err) }
+		os.exec('xcrun simctl launch $device $bundle_id') or { panic(err.msg) }
 	} else {
 		exefile := os.real_path(b.pref.out_name)
 		mut cmd := '"$exefile"'
@@ -133,7 +133,7 @@ fn (mut v Builder) cleanup_run_executable_after_exit(exefile string) {
 	}
 	if os.is_file(exefile) {
 		v.pref.vrun_elog('remove run executable: $exefile')
-		os.rm(exefile) or { panic(err) }
+		os.rm(exefile) or { panic(err.msg) }
 	}
 }
 

vlib/v/builder/js.v

@@ -34,8 +34,8 @@ pub fn (mut b Builder) build_js(v_files []string, out_file string) {
 	b.out_name_js = out_file
 	b.info('build_js($out_file)')
 	output := b.gen_js(v_files)
-	mut f := os.create(out_file) or { panic(err) }
+	mut f := os.create(out_file) or { panic(err.msg) }
-	f.writeln(output) or { panic(err) }
+	f.writeln(output) or { panic(err.msg) }
 	f.close()
 }
 
@@ -58,7 +58,7 @@ fn (mut b Builder) run_js() {
 	cmd := 'node ' + b.pref.out_name + '.js'
 	res := os.exec(cmd) or {
 		println('JS compilation failed.')
-		verror(err)
+		verror(err.msg)
 		return
 	}
 	println(res.output)

vlib/v/builder/msvc.v

@@ -329,7 +329,7 @@ pub fn (mut v Builder) cc_msvc() {
 	// println(res)
 	// println('C OUTPUT:')
 	// Always remove the object file - it is completely unnecessary
-	os.rm(out_name_obj) or { panic(err) }
+	os.rm(out_name_obj) or { panic(err.msg) }
 }
 
 fn (mut v Builder) build_thirdparty_obj_file_with_msvc(path string, moduleflags []cflag.CFlag) {
@@ -369,7 +369,7 @@ fn (mut v Builder) build_thirdparty_obj_file_with_msvc(path string, moduleflags
 	}
 	res := os.exec(cmd) or {
 		println('msvc: failed to execute msvc compiler (to build a thirdparty object); cmd: $cmd')
-		verror(err)
+		verror(err.msg)
 		return
 	}
 	if res.exit_code != 0 {

vlib/v/checker/check_types.v

@@ -318,6 +318,8 @@ pub fn (mut c Checker) fail_if_not_rlocked(expr ast.Expr, what string) {
 }
 
 pub fn (mut c Checker) string_inter_lit(mut node ast.StringInterLiteral) table.Type {
+	inside_println_arg_save := c.inside_println_arg
+	c.inside_println_arg = true
 	for i, expr in node.exprs {
 		ftyp := c.expr(expr)
 		if ftyp.has_flag(.shared_f) {
@@ -365,6 +367,7 @@ pub fn (mut c Checker) string_inter_lit(mut node ast.StringInterLiteral) table.T
 			c.error('cannot call `str()` method recursively', expr.position())
 		}
 	}
+	c.inside_println_arg = inside_println_arg_save
 	return table.string_type
 }
 

vlib/v/checker/checker.v

@@ -2972,7 +2972,7 @@ pub fn (mut c Checker) array_init(mut array_init ast.ArrayInit) table.Type {
 		if array_init.has_default {
 			default_typ := c.expr(array_init.default_expr)
 			c.check_expected(default_typ, array_init.elem_type) or {
-				c.error(err, array_init.default_expr.position())
+				c.error(err.msg, array_init.default_expr.position())
 			}
 		}
 		if sym.kind == .sum_type {
@@ -3459,7 +3459,7 @@ fn (mut c Checker) hash_stmt(mut node ast.HashStmt) {
 		mut flag := node.main
 		if flag.contains('@VROOT') {
 			vroot := util.resolve_vroot(flag, c.file.path) or {
-				c.error(err, node.pos)
+				c.error(err.msg, node.pos)
 				return
 			}
 			node.val = 'include $vroot'
@@ -3468,7 +3468,7 @@ fn (mut c Checker) hash_stmt(mut node ast.HashStmt) {
 		}
 		if flag.contains('\$env(') {
 			env := util.resolve_env_value(flag, true) or {
-				c.error(err, node.pos)
+				c.error(err.msg, node.pos)
 				return
 			}
 			node.main = env
@@ -3486,15 +3486,15 @@ fn (mut c Checker) hash_stmt(mut node ast.HashStmt) {
 			'--cflags --libs $node.main'.split(' ')
 		}
 		mut m := pkgconfig.main(args) or {
-			c.error(err, node.pos)
+			c.error(err.msg, node.pos)
 			return
 		}
 		cflags := m.run() or {
-			c.error(err, node.pos)
+			c.error(err.msg, node.pos)
 			return
 		}
 		c.table.parse_cflag(cflags, c.mod, c.pref.compile_defines_all) or {
-			c.error(err, node.pos)
+			c.error(err.msg, node.pos)
 			return
 		}
 	} else if node.kind == 'flag' {
@@ -3503,13 +3503,13 @@ fn (mut c Checker) hash_stmt(mut node ast.HashStmt) {
 		// expand `@VROOT` to its absolute path
 		if flag.contains('@VROOT') {
 			flag = util.resolve_vroot(flag, c.file.path) or {
-				c.error(err, node.pos)
+				c.error(err.msg, node.pos)
 				return
 			}
 		}
 		if flag.contains('\$env(') {
 			flag = util.resolve_env_value(flag, true) or {
-				c.error(err, node.pos)
+				c.error(err.msg, node.pos)
 				return
 			}
 		}
@@ -3519,7 +3519,9 @@ fn (mut c Checker) hash_stmt(mut node ast.HashStmt) {
 			}
 		}
 		// println('adding flag "$flag"')
-		c.table.parse_cflag(flag, c.mod, c.pref.compile_defines_all) or { c.error(err, node.pos) }
+		c.table.parse_cflag(flag, c.mod, c.pref.compile_defines_all) or {
+			c.error(err.msg, node.pos)
+		}
 	} else {
 		if node.kind != 'define' {
 			c.error('expected `#define`, `#flag`, `#include` or `#pkgconfig` not $node.val',
@@ -3654,7 +3656,7 @@ pub fn (mut c Checker) expr(node ast.Expr) table.Type {
 			return node.typ.to_ptr()
 		}
 		ast.Assoc {
-			v := node.scope.find_var(node.var_name) or { panic(err) }
+			v := node.scope.find_var(node.var_name) or { panic(err.msg) }
 			for i, _ in node.fields {
 				c.expr(node.exprs[i])
 			}
@@ -3951,7 +3953,7 @@ fn (mut c Checker) comptime_call(mut node ast.ComptimeCall) table.Type {
 	node.sym = c.table.get_type_symbol(c.unwrap_generic(c.expr(node.left)))
 	if node.is_env {
 		env_value := util.resolve_env_value("\$env('$node.args_var')", false) or {
-			c.error(err, node.env_pos)
+			c.error(err.msg, node.env_pos)
 			return table.string_type
 		}
 		node.env_value = env_value
@@ -5039,7 +5041,7 @@ fn (mut c Checker) comp_if_branch(cond ast.Expr, pos token.Position) bool {
 						left_type := c.expr(cond.left)
 						right_type := c.expr(cond.right)
 						expr := c.find_definition(cond.left) or {
-							c.error(err, cond.left.pos)
+							c.error(err.msg, cond.left.pos)
 							return false
 						}
 						if !c.check_types(right_type, left_type) {
@@ -5089,7 +5091,7 @@ fn (mut c Checker) comp_if_branch(cond ast.Expr, pos token.Position) bool {
 					return false
 				}
 				expr := c.find_obj_definition(cond.obj) or {
-					c.error(err, cond.pos)
+					c.error(err.msg, cond.pos)
 					return false
 				}
 				if !c.check_types(typ, table.bool_type) {

vlib/v/checker/tests/return_optional_err.out

@@ -1,7 +1,7 @@
 vlib/v/checker/tests/return_optional_err.vv:4:13: error: cannot use `?string` as type `string` in return argument
     2 |
     3 | fn my_func() string {
-    4 |   return os.read_file('/some/file/that/exists.txt') or {panic(err)}
+    4 |   return os.read_file('/some/file/that/exists.txt') or { panic(err.msg) }
       |             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     5 | }
     6 |

vlib/v/checker/tests/return_optional_err.vv

@@ -1,7 +1,7 @@
 import os
 
 fn my_func() string {
-  return os.read_file('/some/file/that/exists.txt') or {panic(err)}
+  return os.read_file('/some/file/that/exists.txt') or { panic(err.msg) }
 }
 
 fn main() {

vlib/v/compiler_errors_test.v

@@ -239,14 +239,14 @@ fn (mut task TaskDescription) execute() {
 	}
 	program := task.path
 	cli_cmd := '$task.vexe $task.voptions $program'
-	res := os.exec(cli_cmd) or { panic(err) }
+	res := os.exec(cli_cmd) or { panic(err.msg) }
 	expected_out_path := program.replace('.vv', '') + task.result_extension
 	task.expected_out_path = expected_out_path
 	task.cli_cmd = cli_cmd
 	if should_autofix && !os.exists(expected_out_path) {
-		os.write_file(expected_out_path, '') or { panic(err) }
+		os.write_file(expected_out_path, '') or { panic(err.msg) }
 	}
-	mut expected := os.read_file(expected_out_path) or { panic(err) }
+	mut expected := os.read_file(expected_out_path) or { panic(err.msg) }
 	task.expected = clean_line_endings(expected)
 	task.found___ = clean_line_endings(res.output)
 	$if windows {
@@ -257,7 +257,7 @@ fn (mut task TaskDescription) execute() {
 	if task.expected != task.found___ {
 		task.is_error = true
 		if should_autofix {
-			os.write_file(expected_out_path, res.output) or { panic(err) }
+			os.write_file(expected_out_path, res.output) or { panic(err.msg) }
 		}
 	}
 }
@@ -279,7 +279,7 @@ fn diff_content(s1 string, s2 string) {
 }
 
 fn get_tests_in_dir(dir string, is_module bool) []string {
-	files := os.ls(dir) or { panic(err) }
+	files := os.ls(dir) or { panic(err.msg) }
 	mut tests := files.clone()
 	if !is_module {
 		tests = files.filter(it.ends_with('.vv'))

vlib/v/doc/doc.v

@@ -353,7 +353,7 @@ pub fn (mut d Doc) generate() ? {
 		os.real_path(os.dir(d.base_path))
 	}
 	d.is_vlib = 'vlib' !in d.base_path
-	project_files := os.ls(d.base_path) or { return error_with_code(err, 0) }
+	project_files := os.ls(d.base_path) or { return err }
 	v_files := d.prefs.should_compile_filtered_files(d.base_path, project_files)
 	if v_files.len == 0 {
 		return error_with_code('vdoc: No valid V files were found.', 1)

vlib/v/fmt/fmt_keep_test.v

@@ -67,7 +67,7 @@ fn test_fmt() {
 				continue
 			}
 			vfmt_result_file := os.join_path(tmpfolder, 'vfmt_run_over_$ifilename')
-			os.write_file(vfmt_result_file, result_ocontent) or { panic(err) }
+			os.write_file(vfmt_result_file, result_ocontent) or { panic(err.msg) }
 			eprintln(util.color_compare_files(diff_cmd, opath, vfmt_result_file))
 			continue
 		}

vlib/v/fmt/fmt_test.v

@@ -59,7 +59,7 @@ fn test_fmt() {
 				continue
 			}
 			vfmt_result_file := os.join_path(tmpfolder, 'vfmt_run_over_$ifilename')
-			os.write_file(vfmt_result_file, result_ocontent) or { panic(err) }
+			os.write_file(vfmt_result_file, result_ocontent) or { panic(err.msg) }
 			eprintln(util.color_compare_files(diff_cmd, opath, vfmt_result_file))
 			continue
 		}

vlib/v/fmt/fmt_vlib_test.v

@@ -57,7 +57,7 @@ fn test_vlib_fmt() {
 				continue
 			}
 			vfmt_result_file := os.join_path(tmpfolder, 'vfmt_run_over_$ifilename')
-			os.write_file(vfmt_result_file, result_ocontent) or { panic(err) }
+			os.write_file(vfmt_result_file, result_ocontent) or { panic(err.msg) }
 			eprintln(util.color_compare_files(diff_cmd, opath, vfmt_result_file))
 			continue
 		}

vlib/v/fmt/tests/chan_ops_keep.vv

@@ -16,7 +16,7 @@ fn get_val_from_chan(ch chan i64) ?i64 {
 fn get_val_from_chan2(ch chan i64) ?i64 {
 	r := <-ch or {
 		println('error')
-		return error(err)
+		return err
 	}
 	return r
 }

vlib/v/fmt/tests/match_keep.vv

@@ -34,13 +34,13 @@ fn branches_are_struct_inits() {
 
 fn branches_are_call_exprs_with_or_blocks() {
 	match 'a' {
-		'b' { foo() or { panic(err) } }
+		'b' { foo() or { panic(err.msg) } }
 	}
 	match 'a' {
 		'b' {
 			foo() or {
 				// do stuff
-				panic(err)
+				panic(err.msg)
 			}
 		}
 	}
@@ -48,7 +48,7 @@ fn branches_are_call_exprs_with_or_blocks() {
 		'b' {
 			foo() or {
 				another_stmt()
-				panic(err)
+				panic(err.msg)
 			}
 		}
 	}

vlib/v/gen/c/cgen.v

@@ -648,7 +648,9 @@ static inline $opt_el_type __Option2_${styp}_popval($styp ch) {
 	$opt_el_type _tmp = {0};
 	if (sync__Channel_try_pop_priv(ch, _tmp.data, false)) {
 		Option2 _tmp2 = error2(_SLIT("channel closed"));
-		return *($opt_el_type*)&_tmp2;
+		$opt_el_type _tmp3;
+		memcpy(&_tmp3, &_tmp2, sizeof(Option2));
+		return _tmp3;
 	}
 	return _tmp;
 }')
@@ -662,7 +664,9 @@ fn (mut g Gen) register_chan_push_optional_call(el_type string, styp string) {
 static inline Option2_void __Option2_${styp}_pushval($styp ch, $el_type e) {
 	if (sync__Channel_try_push_priv(ch, &e, false)) {
 		Option2 _tmp2 = error2(_SLIT("channel closed"));
-		return *(Option2_void*)&_tmp2;
+		Option2_void _tmp3;
+		memcpy(&_tmp3, &_tmp2, sizeof(Option2));
+		return _tmp3;
 	}
 	return (Option2_void){0};
 }')
@@ -5571,7 +5575,7 @@ fn (mut g Gen) or_block(var_name string, or_block ast.OrExpr, return_type table.
 		}
 	} else if or_block.kind == .propagate {
 		if g.file.mod.name == 'main' && (isnil(g.fn_decl) || g.fn_decl.name == 'main.main') {
-			// In main(), an `opt()?` call is sugar for `opt() or { panic(err) }`
+			// In main(), an `opt()?` call is sugar for `opt() or { panic(err.msg) }`
 			if g.pref.is_debug {
 				paline, pafile, pamod, pafn := g.panic_debug_info(or_block.pos)
 				g.writeln('panic_debug($paline, tos3("$pafile"), tos3("$pamod"), tos3("$pafn"), ${cvar_name}.err.msg );')
@@ -5580,7 +5584,7 @@ fn (mut g Gen) or_block(var_name string, or_block ast.OrExpr, return_type table.
 			}
 		} else {
 			// In ordinary functions, `opt()?` call is sugar for:
-			// `opt() or { return error(err) }`
+			// `opt() or { return err }`
 			// Since we *do* return, first we have to ensure that
 			// the defered statements are generated.
 			g.write_defer_stmts()

vlib/v/gen/c/cgen_test.v

@@ -18,7 +18,7 @@ fn test_c_files() {
 	vroot := os.dir(vexe)
 	for i in 1 .. (nr_tests + 1) {
 		path := '$vroot/vlib/v/gen/tests/${i}.vv'
-		ctext := os.read_file('$vroot/vlib/v/gen/tests/${i}.c') or { panic(err) }
+		ctext := os.read_file('$vroot/vlib/v/gen/tests/${i}.c') or { panic(err.msg) }
 		mut b := builder.new_builder(&pref.Preferences{})
 		b.module_search_paths = ['$vroot/vlib/v/gen/tests/']
 		mut res := b.gen_c([path]).after('#endbuiltin')

vlib/v/gen/c/comptime.v

@@ -237,7 +237,7 @@ fn (mut g Gen) comp_if_cond(cond ast.Expr) bool {
 		}
 		ast.PostfixExpr {
 			ifdef := g.comp_if_to_ifdef((cond.expr as ast.Ident).name, true) or {
-				verror(err)
+				verror(err.msg)
 				return false
 			}
 			g.write('defined($ifdef)')

vlib/v/gen/js/jsgen_test.v

@@ -15,7 +15,7 @@ const there_is_node_available = is_nodejs_working()
 fn test_example_compilation() {
 	vexe := os.getenv('VEXE')
 	os.chdir(os.dir(vexe))
-	os.mkdir_all(output_dir) or { panic(err) }
+	os.mkdir_all(output_dir) or { panic(err.msg) }
 	files := find_test_files()
 	for file in files {
 		path := os.join_path(test_dir, file)
@@ -40,7 +40,7 @@ fn test_example_compilation() {
 }
 
 fn find_test_files() []string {
-	files := os.ls(test_dir) or { panic(err) }
+	files := os.ls(test_dir) or { panic(err.msg) }
 	// The life example never exits, so tests would hang with it, skip
 	mut tests := files.filter(it.ends_with('.v')).filter(it != 'life.v')
 	tests.sort()

vlib/v/gen/js/tests/js.v

@@ -88,7 +88,7 @@ fn main() {
 		println(message)
 	})
 	hl.raw_js_log()
-	propagation() or { println(err) }
+	propagation() or { println(err.msg) }
 }
 
 fn anon_consumer(greeting string, anon fn (message string)) {

vlib/v/gen/x64/elf.v

@@ -99,7 +99,7 @@ pub fn (mut g Gen) generate_elf_footer() {
 	// -5 is for "e8 00 00 00 00"
 	g.write32_at(g.code_start_pos + 1, int(g.main_fn_addr - g.code_start_pos) - 5)
 	// Create the binary
-	mut f := os.create(g.out_name) or { panic(err) }
+	mut f := os.create(g.out_name) or { panic(err.msg) }
 	os.chmod(g.out_name, 0o775) // make it an executable
 	unsafe { f.write_bytes(g.buf.data, g.buf.len) }
 	f.close()

vlib/v/gen/x64/tests/x64_test.v

@@ -15,10 +15,10 @@ fn test_x64() {
 	vexe := os.getenv('VEXE')
 	vroot := os.dir(vexe)
 	dir := os.join_path(vroot, 'vlib/v/gen/x64/tests')
-	files := os.ls(dir) or { panic(err) }
+	files := os.ls(dir) or { panic(err.msg) }
 	//
 	wrkdir := os.join_path(os.temp_dir(), 'vtests', 'x64')
-	os.mkdir_all(wrkdir) or { panic(err) }
+	os.mkdir_all(wrkdir) or { panic(err.msg) }
 	os.chdir(wrkdir)
 	tests := files.filter(it.ends_with('.vv'))
 	if tests.len == 0 {
@@ -46,7 +46,7 @@ fn test_x64() {
 			eprintln(res.output)
 			continue
 		}
-		mut expected := os.read_file('$dir/${test}.out') or { panic(err) }
+		mut expected := os.read_file('$dir/${test}.out') or { panic(err.msg) }
 		expected = expected.trim_right('\r\n').replace('\r\n', '\n')
 		mut found := res.output.trim_right('\r\n').replace('\r\n', '\n')
 		found = found.trim_space()

vlib/v/live/live_test.v

@@ -44,7 +44,7 @@ const (
 )
 
 fn get_source_template() string {
-	src := os.read_file(os.join_path(os.dir(@FILE), 'live_test_template.vv')) or { panic(err) }
+	src := os.read_file(os.join_path(os.dir(@FILE), 'live_test_template.vv')) or { panic(err.msg) }
 	return src.replace('#OUTPUT_FILE#', output_file)
 }
 
@@ -60,8 +60,8 @@ fn atomic_write_source(source string) {
 	// NB: here wrtiting is done in 2 steps, since os.write_file can take some time,
 	// during which the file will be modified, but it will still be not completely written.
 	// The os.mv after that, guarantees that the reloader will see a complete valid V program.
-	os.write_file(tmp_file, source) or { panic(err) }
+	os.write_file(tmp_file, source) or { panic(err.msg) }
-	os.mv(tmp_file, source_file) or { panic(err) }
+	os.mv(tmp_file, source_file) or { panic(err.msg) }
 }
 
 //

vlib/v/parser/parser.v

@@ -152,7 +152,7 @@ pub fn parse_file(path string, table &table.Table, comments_mode scanner.Comment
 	// for handling them, and should be removed when we do (the general solution is also needed for vfmt)
 	// println('parse_file("$path")')
 	// text := os.read_file(path) or {
-	// panic(err)
+	// panic(err.msg)
 	// }
 	mut p := Parser{
 		scanner: scanner.new_scanner_file(path, comments_mode, pref)

vlib/v/pkgconfig/main.v

@@ -83,7 +83,7 @@ pub fn (mut m Main) run() ?string {
 	for arg in opt.args {
 		mut pcdep := load(arg, options) or {
 			if !opt.exists {
-				return error(err)
+				return err
 			}
 			continue
 		}

vlib/v/pkgconfig/pkgconfig.v

@@ -245,7 +245,7 @@ pub fn load(pkgname string, options Options) ?&PkgConfig {
 		options: options
 	}
 	pc.load_paths()
-	file := pc.resolve(pkgname) or { return error(err) }
+	file := pc.resolve(pkgname) or { return err }
 	if !pc.parse(file) {
 		return error('file "$file" could not be parsed')
 	}