--- a/python/mach_commands.py
+++ b/python/mach_commands.py
@@ -141,29 +141,32 @@ class MachCommands(MachCommandBase):
 
         return_code = 0
         with ThreadPoolExecutor(max_workers=self.jobs) as executor:
             futures = [executor.submit(self._run_python_test, test['path'])
                        for test in tests]
 
             try:
                 for future in as_completed(futures):
-                    output, ret = future.result()
+                    output, ret, test_path = future.result()
 
                     for line in output:
                         self.log(logging.INFO, 'python-test', {'line': line.rstrip()}, '{line}')
 
+                    if ret and not return_code:
+                        self.log(logging.ERROR, 'python-test', {'test_path': test_path, 'ret': ret}, 'Setting retcode to {ret} from {test_path}')
                     return_code = return_code or ret
             except KeyboardInterrupt:
                 # Hack to force stop currently running threads.
                 # https://gist.github.com/clchiou/f2608cbe54403edb0b13
                 executor._threads.clear()
                 thread._threads_queues.clear()
                 raise
 
+        self.log(logging.INFO, 'python-test', {'return_code': return_code}, 'Return code from mach python-test: {return_code}')
         return return_code
 
     def _run_python_test(self, test_path):
         from mozprocess import ProcessHandler
 
         output = []
 
         def _log(line):
@@ -199,9 +202,9 @@ class MachCommands(MachCommandBase):
                  'call?): {}'.format(test_path))
 
         if self.verbose:
             if return_code != 0:
                 _log('Test failed: {}'.format(test_path))
             else:
                 _log('Test passed: {}'.format(test_path))
 
-        return output, return_code
+        return output, return_code, test_path

--- a/testing/testsuite-targets.mk
+++ b/testing/testsuite-targets.mk
@@ -309,17 +309,19 @@ TEST_EXTENSIONS := \
 
 stage-extensions: make-stage-dir
 	$(NSINSTALL) -D $(PKG_STAGE)/extensions/
 	@$(foreach ext,$(TEST_EXTENSIONS), cp -RL $(DIST)/xpi-stage/$(ext) $(PKG_STAGE)/extensions;)
 
 
 check::
 	$(eval cores=$(shell $(PYTHON) -c 'import multiprocessing; print(multiprocessing.cpu_count())'))
+	@echo "Starting 'mach python-test' with -j$(cores)"
 	@$(topsrcdir)/mach --log-no-times python-test -j$(cores)
+	@echo "Finished 'mach python-test' successfully"
 
 
 .PHONY: \
   reftest \
   crashtest \
   xpcshell-tests \
   jstestbrowser \
   package-tests \