I ran into a test failure on the XVR tests in [1] which looked like the test was executing with a python docker container that did _not_ include the python changes in my PR. The test ran successfully after a second run.
It seems likely that the initial failure occurred because some other job was running concurrently on the same jenkins worker and overwrote the ` apache/beam_python2.7_sdk:2.21.0.dev` image that my run had generated. Is this possible? If so, is there something we should do to isolate these images? [1] https://github.com/apache/beam/pull/10055
