PyDrive backend not working due to missing imports

[austinkeller]

Attempting a backup with the PyDrive backend gives the following error:

$ docker run --rm --user $UID -e GOOGLE_DRIVE_ACCOUNT_KEY -v /home/austin/.cache:/home/duplicity/.cache/duplicity -v /home/austin/.gnupg:/home/duplicity/.gnupg -v /home/austin/data:/data:ro wernight/duplicity duplicity --allow-source-mismatch --full-if-older-than=6M --no-encryption /data pydrive://duplicity@myproject-00000.iam.gserviceaccount.com/duplicity
BackendException: PyDrive backend requires PyDrive and Google API client installation.                                                                                                                             
Please read the manpage for setup details.                                                                                                                                                                         
Exception: No module named 'pkg_resources'