./run-all-tests 'heptapod.testhelpers' is not a package
Steps to reproduce:
$ hg clone https://foss.heptapod.net/heptapod/hgitaly
$ virtualenv --python=python3 virtualenv
$ source virtualenv/bin/activate
$ pip install -r test-requirements.txt
...
Successfully installed Mercurial-5.6.1 attrs-20.3.0 coverage-5.3.1 dulwich-0.20.14 flake8-3.8.4 grpcio-1.34.0 heptapod-2.1.1 hg-evolve-10.1.0 hg-git-0.9.0 hg-loggingmod-0.2.0 iniconfig-1.1.1 mccabe-0.6.1 mercurial-testhelpers-0.4.0 pluggy-0.13.1 protobuf-3.14.0 py-1.10.0 pycodestyle-2.6.0 pyflakes-2.2.0 pytest-6.2.1 pytest-cov-2.10.1 pytest-grpc-0.8.0 requests-unixsocket-0.2.0 toml-0.10.2
$ ./run-all-tests
ImportError while loading conftest '/home/loic/software/heptapod/hgitaly/tests_with_gitaly/conftest.py'.
tests_with_gitaly/conftest.py:33: in <module>
from .comparison import gitaly_comparison_fixture
tests_with_gitaly/comparison.py:12: in <module>
from heptapod.testhelpers.gitlab import GitLabMirrorFixture
E ModuleNotFoundError: No module named 'heptapod.testhelpers.gitlab'; 'heptapod.testhelpers' is not a package