Nicer timeout error messages

Tell *which* lock timed out, too. This should help with debugging.

Author: Frerich Raabe

clcache.py

@@ -263,9 +263,9 @@ def acquire(self):
         if result not in [0, self.WAIT_ABANDONED_CODE]:
             if result == self.WAIT_TIMEOUT_CODE:
                 errorString = \
-                    'Failed to acquire cache lock after {}ms; ' \
+                    'Failed to acquire lock {} after {}ms; ' \
                     'try setting CLCACHE_OBJECT_CACHE_TIMEOUT_MS environment variable to a larger value.'.format(
-                        self._timeoutMs)
+                        self._mutexName, self._timeoutMs)
             else:
                 errorString = 'Error! WaitForSingleObject returns {result}, last error {error}'.format(
                     result=result,