Trac #30671: Random failure in src/sage/interfaces/psage.py

Clearly the dtor is racing with the sage-cleaner process that is
deleting the temporary directory:
{{{
File "src/sage/interfaces/psage.py", line 114, in
sage.interfaces.psage.PSage.__del__
Failed example:
    PSage().__del__()
Expected nothing
Got:
    Exception ignored in: <function ExpectElement.__del__ at 0xd14d6388>
    Traceback (most recent call last):
      File "/home/buildbot/slave/sage_git/build/local/lib/python3.8
/site-packages/sage/interfaces/expect.py", line 1513, in __del__
        P.clear(self._name)
      File "/home/buildbot/slave/sage_git/build/local/lib/python3.8
/site-packages/sage/interfaces/sage0.py", line 369, in clear
        self.eval('del %s' % var)
      File "/home/buildbot/slave/sage_git/build/local/lib/python3.8
/site-packages/sage/interfaces/psage.py", line 129, in eval
        if self.is_locked():
      File "/home/buildbot/slave/sage_git/build/local/lib/python3.8
/site-packages/sage/interfaces/psage.py", line 97, in is_locked
        with open(self.__tmp) as fobj:
    FileNotFoundError: [Errno 2] No such file or directory: '/home/build
bot/slave/sage_git/dot_sage/temp/sagebu16_32s02/3311/sage_smpux8mxorv//l
ock'
**********************************************************************
1 item had failures:
   1 of   2 in sage.interfaces.psage.PSage.__del__
    [7 tests, 1 failure, 4.76 s]
}}}

URL: https://trac.sagemath.org/30671
Reported by: vbraun
Ticket author(s): Markus Wageringel
Reviewer(s): Volker Braun

src/sage/interfaces/psage.py

@@ -113,10 +113,21 @@ def __del__(self):
 
             sage: PSage().__del__()
         """
-        if os.path.exists(self.__tmp_dir):
-            for x in os.listdir(self.__tmp_dir):
-                os.remove(os.path.join(self.__tmp_dir, x))
+        try:
+            files = os.listdir(self.__tmp_dir)
+        except OSError:
+            pass
+        else:
+            for x in files:
+                try:
+                    os.remove(os.path.join(self.__tmp_dir, x))
+                except OSError:
+                    pass
+        try:
             os.removedirs(self.__tmp_dir)
+        except OSError:
+            pass
+
         if not (self._expect is None):
             cmd = 'kill -9 %s'%self._expect.pid
             os.system(cmd)