diff --git a/ports/winit/main2.rs b/ports/winit/main2.rs
index 07d931c21abb6..2cccdb9550df5 100644
--- a/ports/winit/main2.rs
+++ b/ports/winit/main2.rs
@@ -117,11 +117,11 @@ pub fn main() {
         };
         let current_thread = thread::current();
         let name = current_thread.name().unwrap_or("<unnamed>");
-        let stdout = std::io::stdout();
-        let mut stdout = stdout.lock();
+        let stderr = std::io::stderr();
+        let mut stderr = stderr.lock();
         if let Some(location) = info.location() {
             let _ = writeln!(
-                &mut stdout,
+                &mut stderr,
                 "{} (thread {}, at {}:{})",
                 msg,
                 name,
@@ -129,12 +129,16 @@ pub fn main() {
                 location.line()
             );
         } else {
-            let _ = writeln!(&mut stdout, "{} (thread {})", msg, name);
+            let _ = writeln!(&mut stderr, "{} (thread {})", msg, name);
         }
         if env::var("RUST_BACKTRACE").is_ok() {
-            let _ = backtrace::print(&mut stdout);
+            let _ = backtrace::print(&mut stderr);
+        }
+        drop(stderr);
+
+        if opts::get().hard_fail && !opts::get().multiprocess {
+            std::process::exit(1);
         }
-        drop(stdout);
 
         error!("{}", msg);
     }));
diff --git a/python/wpt/grouping_formatter.py b/python/wpt/grouping_formatter.py
index fcf9fcbe69dd5..4e14d62b5735b 100644
--- a/python/wpt/grouping_formatter.py
+++ b/python/wpt/grouping_formatter.py
@@ -216,10 +216,8 @@ def test_status(self, data: dict):
         ))
 
     def process_output(self, data):
-        if data['thread'] not in self.running_tests:
-            return
-        test_name = self.running_tests[data['thread']]
-        self.test_output[test_name] += data['data'] + "\n"
+        if 'test' in data:
+            self.test_output[data['test']] += data['data'] + "\n"
 
     def log(self, _):
         pass
diff --git a/tests/wpt/meta/MANIFEST.json b/tests/wpt/meta/MANIFEST.json
index 833b804569bc7..045d0b4f0d609 100644
--- a/tests/wpt/meta/MANIFEST.json
+++ b/tests/wpt/meta/MANIFEST.json
@@ -465041,7 +465041,7 @@
         []
        ],
        "executorservo.py": [
-        "a8ec38699616c5baf7a3b43b8149b89746308f35",
+        "0d22471e90e83fbfd80010001e8c60f509af8902",
         []
        ],
        "executorservodriver.py": [
diff --git a/tests/wpt/tests/tools/wptrunner/wptrunner/executors/executorservo.py b/tests/wpt/tests/tools/wptrunner/wptrunner/executors/executorservo.py
index a8ec38699616c..0d22471e90e83 100644
--- a/tests/wpt/tests/tools/wptrunner/wptrunner/executors/executorservo.py
+++ b/tests/wpt/tests/tools/wptrunner/wptrunner/executors/executorservo.py
@@ -83,6 +83,7 @@ def teardown(self):
         ProcessTestExecutor.teardown(self)
 
     def do_test(self, test):
+        self.test = test
         self.result_data = None
         self.result_flag = threading.Event()
 
@@ -156,7 +157,7 @@ def on_output(self, line):
             else:
                 self.logger.process_output(self.proc.pid,
                                            line,
-                                           " ".join(self.command))
+                                           " ".join(self.command), self.test.url)
 
     def on_finish(self):
         self.result_flag.set()
@@ -270,18 +271,19 @@ def screenshot(self, test, viewport_size, dpi, page_ranges):
                 return True, [base64.b64encode(data).decode()]
 
     def do_test(self, test):
+        self.test = test
         result = self.implementation.run_test(test)
 
         return self.convert_result(test, result)
 
-    def on_output(self, line):
+    def on_output(line):
         line = line.decode("utf8", "replace")
         if self.interactive:
             print(line)
         else:
             self.logger.process_output(self.proc.pid,
                                        line,
-                                       " ".join(self.command))
+                                   " ".join(self.command), self.test.url)
 
 
 class ServoTimedRunner(TimedRunner):
@@ -342,7 +344,7 @@ def do_crashtest(self, protocol, url, timeout):
         env["HOST_FILE"] = self.hosts_path
         env["RUST_BACKTRACE"] = "1"
 
-        command = build_servo_command(self.test,
+        self.command = build_servo_command(self.test,
                                       self.test_url,
                                       self.browser,
                                       self.binary,
@@ -351,12 +353,13 @@ def do_crashtest(self, protocol, url, timeout):
                                       extra_args=["-x"])
 
         if not self.interactive:
-            self.proc = ProcessHandler(command,
+            self.proc = ProcessHandler(self.command,
                                        env=env,
+                                       processOutputLine=[self.on_output],
                                        storeOutput=False)
             self.proc.run()
         else:
-            self.proc = subprocess.Popen(command, env=env)
+            self.proc = subprocess.Popen(self.command, env=env)
 
         self.proc.wait()
 
@@ -364,3 +367,9 @@ def do_crashtest(self, protocol, url, timeout):
             return {"status": "PASS", "message": None}
 
         return {"status": "CRASH", "message": None}
+
+    def on_output(self, line):
+        line = line.decode("utf8", "replace")
+        self.logger.process_output(self.proc.pid,
+                                   line,
+                                   " ".join(self.command), self.test.url)