Bazel builds seem to not have a .coveragerc. This file has been around for a while so I don't think it's a version issue.

bazel build //google/cloud/documentai/v1beta2:documentai-v1beta2-py

Contents of tar (just missing .coveragerc)

$ ls -a
.  ..  docs  google  MANIFEST.in  mypy.ini  noxfile.py  scripts  setup.py  tests

Resolved in #550: Unit test subdirs are also missing the __init__.py. https://github.com/googleapis/gapic-generator-python/blob/master/gapic/templates/tests/unit/gapic/%25name_%25version/%25sub/__init__.py

CC @vam-google