Sporadic "resource deadlock avoided" errors for GCE credentials

In the last few days I've been getting this error sporadically when trying to copy files from GCS onto local storage on GCE nodes:

```
Your "GCE" credentials are invalid. Please run
$ gcloud auth login
[Errno 35] Resource deadlock avoided
CommandException: Some components of [redacted] were not downloaded successfully. Please retry this download.
CommandException: 1 file/object could not be transferred.
```

It is unclear to me whether this is related to the metadata connection mentioned above, the [locking bug fixed in oauth2client a couple years ago](https://github.com/google/oauth2client/issues/335), or something else entirely.