util: handle ENOENT in _stripcwd() listdir loop

After we call listdir(), another thread or process might delete files
from the current directory. We cannot always expect lstat() to succeed
in a loop over the initial listdir entries.

If lstat() raises ENOENT, consider this file deleted and move on.

koji/util.py

@@ -23,6 +23,7 @@ from __future__ import absolute_import, division
 import base64
 import calendar
 import datetime
+import errno
 import hashlib
 import logging
 import os
@@ -472,7 +473,12 @@ def _stripcwd(dev):
     """Unlink all files in cwd and return list of subdirs"""
     dirs = []
     for fn in os.listdir('.'):
-        st = os.lstat(fn)
+        try:
+            st = os.lstat(fn)
+        except OSError as e:
+            if e.errno == errno.ENOENT:
+                continue
+            raise
         if st.st_dev != dev:
             # don't cross fs boundary
             continue