Fix #47

mjtest/environment.py

 import logging
 import os
 import random
+import shlex
 import shutil
 import tempfile
 from datetime import datetime
 import time
+from threading import Timer
 from typing import Dict
 
+import subprocess
+
 from mjtest.util.shell import execute
 from mjtest.util.utils import get_mjtest_basedir, force_colored_output
 import mjtest.util.utils
@@ -201,3 +205,29 @@ class Environment:
             raise
         return dst_file
 
+    def run_command_till_timeout(self, cmd: str, *args: Tuple[str], timeout: float = 0) -> Tuple[bytes, bytes, int, bool]:
+        """
+        Much slower than `run_command` but captures the command output even when a
+        timeout occurs.
+
+        Inspired by http://stackoverflow.com/a/10768774
+        """
+        cmds = [cmd] + list(args)
+        cmds = [shlex.quote(c) for c in cmds]
+        proc = subprocess.Popen(cmds, stdout=subprocess.PIPE,
+                                stderr=subprocess.PIPE)
+        timeouted = False
+
+        def kill_proc(proc):
+            timeouted = True
+            proc.kill()
+
+        stdout, stderr = None, None
+        if timeout >= 0.0:
+            timer = Timer(timeout, kill_proc, [proc])
+            timer.start()
+            stdout, stderr = proc.communicate()
+            timer.cancel()
+        else:
+            stdout, stderr = proc.communicate()
+        return stdout, stderr, proc.returncode, timeouted
\ No newline at end of file

mjtest/test/exec_tests.py

@@ -206,6 +206,7 @@ class JavaInfiniteLoopTest(BasicSyntaxTest):
                 return test_result
         except SigKill as sig:
             if sig.retcode == signal.SIGXCPU:
+                out, _, _, _ = self.env.run_command_till_timeout("./" + base_filename, timeout=1)
                 test_result.add_long_text("Output", out.decode())
                 if self._has_output_file:
                     out = out.decode().strip()