diff --git a/cmd/tools/test_os_process.v b/cmd/tools/test_os_process.v
index 7424120202..e1f5a17db6 100644
--- a/cmd/tools/test_os_process.v
+++ b/cmd/tools/test_os_process.v
@@ -88,9 +88,11 @@ fn main() {
 		}
 	}
 	spawn do_timeout(&ctx)
+	ctx.println('start')
 	for i := 1; true; i++ {
 		ctx.println('${i}')
 		time.sleep(ctx.period_ms * time.millisecond)
 	}
+	ctx.println('done')
 	time.sleep(100 * time.second)
 }
diff --git a/vlib/os/process_test.v b/vlib/os/process_test.v
index dc9edee4ff..eee6d69b62 100644
--- a/vlib/os/process_test.v
+++ b/vlib/os/process_test.v
@@ -27,12 +27,14 @@ fn testsuite_end() {
 }
 
 fn test_getpid() {
+	eprintln(@FN)
 	pid := os.getpid()
 	eprintln('current pid: ${pid}')
 	assert pid != 0
 }
 
 fn test_set_work_folder() {
+	eprintln(@FN)
 	new_work_folder := os.real_path(os.temp_dir())
 	parent_working_folder := os.getwd()
 	dump(new_work_folder)
@@ -62,6 +64,7 @@ fn test_set_work_folder() {
 }
 
 fn test_set_environment() {
+	eprintln(@FN)
 	mut p := os.new_process(test_os_process)
 	p.set_args(['-show_env', '-target', 'stdout'])
 	p.set_environment({
@@ -75,11 +78,11 @@ fn test_set_environment() {
 	$if trace_process_output ? {
 		eprintln('p output: "${output}"')
 	}
-	dump(output)
-	assert output.contains('V_OS_TEST_PORT=1234567890')
+	assert output.contains('V_OS_TEST_PORT=1234567890'), output
 }
 
 fn test_run() {
+	eprintln(@FN)
 	mut p := os.new_process(test_os_process)
 	p.set_args(['-timeout_ms', '150', '-period_ms', '50'])
 	p.run()
@@ -107,6 +110,7 @@ fn test_run() {
 }
 
 fn test_wait() {
+	eprintln(@FN)
 	mut p := os.new_process(test_os_process)
 	assert p.status != .exited
 	p.wait()
@@ -117,8 +121,9 @@ fn test_wait() {
 }
 
 fn test_slurping_output() {
+	eprintln(@FN)
 	mut p := os.new_process(test_os_process)
-	p.set_args(['-timeout_ms', '500', '-period_ms', '50'])
+	p.set_args(['-timeout_ms', '600', '-period_ms', '50'])
 	p.set_redirect_stdio()
 	assert p.status != .exited
 	p.wait()
@@ -133,15 +138,12 @@ fn test_slurping_output() {
 		eprintln('p errors: "${errors}"')
 		eprintln('---------------------------')
 	}
-	// dump(output)
-	assert output.contains('stdout, 1')
-	assert output.contains('stdout, 2')
-	assert output.contains('stdout, 3')
-	assert output.contains('stdout, 4')
-
-	// dump(errors)
-	assert errors.contains('stderr, 1')
-	assert errors.contains('stderr, 2')
-	assert errors.contains('stderr, 3')
-	assert errors.contains('stderr, 4')
+	assert output.contains('stdout, 1'), output
+	assert output.contains('stdout, 2'), output
+	assert output.contains('stdout, 3'), output
+	assert output.contains('stdout, 4'), output
+	assert errors.contains('stderr, 1'), errors
+	assert errors.contains('stderr, 2'), errors
+	assert errors.contains('stderr, 3'), errors
+	assert errors.contains('stderr, 4'), errors
 }