use ignore_errors=True workaround for test teardown cleanup, see #862

borg/testsuite/archiver.py

@@ -218,7 +218,8 @@ class ArchiverTestCaseBase(BaseTestCase):
 
     def tearDown(self):
         os.chdir(self._old_wd)
-        shutil.rmtree(self.tmpdir)
+        # note: ignore_errors=True as workaround for issue #862
+        shutil.rmtree(self.tmpdir, ignore_errors=True)
 
     def cmd(self, *args, **kw):
         exit_code = kw.pop('exit_code', 0)