Add some logs to investigate minimization issues and disable multi th… (#4648)

…read runs

Author: alhijazi

src/clusterfuzz/_internal/bot/minimizer/minimizer.py

@@ -183,6 +183,7 @@ def _deadline_exceeded(self, cleanup_function=None, soft_check=False):
     """Check to see if we have exceeded the deadline for execution."""
     if self.minimizer.deadline and time.time() > self.minimizer.deadline:
       if soft_check:
+        logs.warning(f'Minimization deadline exceeded. soft_check={soft_check}')
         return True
 
       # If we are here, we have exceeded the deadline on a hard check. Clean up.
@@ -192,6 +193,7 @@ def _deadline_exceeded(self, cleanup_function=None, soft_check=False):
       if self.minimizer.cleanup_function:
         self.minimizer.cleanup_function()
 
+      logs.warning('Minimization deadline exceeded.')
       # Raise an exception if this is not a soft deadline check.
       raise errors.MinimizationDeadlineExceededError(self)
 
@@ -558,6 +560,7 @@ def minimize(self, data):
       # minimized test case is stored with it so that we can recover the work
       # that had been done up to that point.
       testcase = error.testcase
+      logs.warning('Minimization Deadline Exceeded.')
     except errors.TokenizationFailureError:
       logs.info('Tokenized data did not match original data. Defaulting to line'
                 'minimization.')

src/clusterfuzz/_internal/bot/tasks/utasks/minimize_task.py

@@ -445,7 +445,10 @@ def utask_main(uworker_input: uworker_msg_pb2.Input):  # pylint: disable=no-memb
         ' should have been detected in preprocess.')
     return None
 
-  max_threads = utils.maximum_parallel_processes_allowed()
+  # TODO(alhijazi): re-install multithreaded runs
+  # max_threads = utils.maximum_parallel_processes_allowed()
+  # Temporarily run minimization single threaded.
+  max_threads = 1
 
   # Prepare the test case runner.
   crash_retries = environment.get_value('CRASH_RETRIES')
@@ -1748,8 +1751,10 @@ def do_html_minimization(test_function, get_temp_file, data, deadline, threads,
       delete_temp_files=delete_temp_files,
       progress_report_function=logs.info)
   try:
+    logs.info('Launching html minimization.')
     return current_minimizer.minimize(data)
   except minimizer_errors.AntlrDecodeError:
+    logs.info('Launching line minimization.')
     return do_line_minimization(test_function, get_temp_file, data, deadline,
                                 threads, cleanup_interval, delete_temp_files)