fix live_test.v on windows

vlib/v/live/live_test.v

@@ -36,7 +36,7 @@ const vtmp_folder = os.join_path(os.vtmp_dir(), 'live_tests')
 const main_source_file = os.join_path(vtmp_folder, 'main.v')
 const tmp_file = os.join_path(vtmp_folder, 'mymodule', 'generated_live_module.tmp')
 const source_file = os.join_path(vtmp_folder, 'mymodule', 'mymodule.v')
-const genexe_file = os.join_path(vtmp_folder, 'generated_live_program')
+const genexe_file = os.join_path(vtmp_folder, 'generated_live_program.exe')
 const output_file = os.join_path(vtmp_folder, 'generated_live_program.output.txt')
 const res_original_file = os.join_path(vtmp_folder, 'ORIGINAL.txt')
 const res_changed_file = os.join_path(vtmp_folder, 'CHANGED.txt')
@@ -46,7 +46,7 @@ const live_program_source = get_source_template()
 
 fn get_source_template() string {
 	src := os.read_file(os.join_path(os.dir(@FILE), 'live_test_template.vv')) or { panic(err) }
-	return src.replace('#OUTPUT_FILE#', output_file)
+	return src.replace('#OUTPUT_FILE#', output_file.replace('\\', '\\\\'))
 }
 
 fn atomic_write_source(source string) {
@@ -168,19 +168,30 @@ fn setup_cycles_environment() {
 	os.setenv('WAIT_CYCLES', '${max_wait_cycles}', true)
 }
 
-//
+fn run_in_background(cmd string) {
+	spawn fn (cmd string) {
+		res := os.execute(cmd)
+		if res.exit_code != 0 {
+			eprintln('----------------------- background command failed: --------------------------')
+			eprintln('----- exit_code: ${res.exit_code}, cmd: ${cmd}, output:')
+			eprintln(res.output)
+			eprintln('-----------------------------------------------------------------------------')
+		}
+		assert res.exit_code == 0
+	}(cmd)
+	time.sleep(1000 * time.millisecond)
+	eprintln('... run_in_background, cmd: ${cmd}')
+}
+
 fn test_live_program_can_be_compiled() {
 	setup_cycles_environment()
 	eprintln('Compiling...')
 	compile_cmd := '${os.quoted_path(vexe)} -cg -keepc -nocolor -live -o ${os.quoted_path(genexe_file)} ${os.quoted_path(main_source_file)}'
 	eprintln('> compile_cmd: ${compile_cmd}')
-	os.system(compile_cmd)
-
-	cmd := '${os.quoted_path(genexe_file)} > /dev/null &'
-	eprintln('Running with: ${cmd}')
-	res := os.system(cmd)
-	assert res == 0
-	eprintln('... running in the background')
+	time.sleep(1000 * time.millisecond) // improve chances of working on windows
+	compile_res := os.system(compile_cmd)
+	assert compile_res == 0
+	run_in_background('${os.quoted_path(genexe_file)}')
 	wait_for_file('ORIGINAL')
 }