Comment 1 for bug 2040498

appears to also happen on Focal:

unit-kata-1: 13:37:57 WARNING unit.kata/1.install Looking in links: wheelhouse
unit-kata-1: 13:37:57 WARNING unit.kata/1.install ERROR: Could not find a version that satisfies the requirement flit_core<4,>=3.2 (from versions: none)
unit-kata-1: 13:37:57 WARNING unit.kata/1.install ERROR: No matching distribution found for flit_core<4,>=3.2
unit-kata-1: 13:37:57 WARNING unit.kata/1.install ----------------------------------------
unit-kata-1: 13:37:57 WARNING unit.kata/1.install ERROR: Command errored out with exit status 1: /var/lib/juju/agents/unit-kata-1/.venv/bin/python /var/lib/juju/agents/unit-kata-1/.venv/lib/python3.8/site-packages/pip install --ignore-installed --no-user --prefix /tmp/pip-build-env-ei4xp3d5/overlay --no-warn-script-location --no-binary :none: --only-binary :none: --no-index --find-links wheelhouse -- 'flit_core >=3.2,<4' Check the logs for full command output.
unit-kata-1: 13:37:57 WARNING unit.kata/1.install Traceback (most recent call last):
unit-kata-1: 13:37:57 WARNING unit.kata/1.install File "/var/lib/juju/agents/unit-kata-1/charm/hooks/install", line 8, in <module>
unit-kata-1: 13:37:57 WARNING unit.kata/1.install basic.bootstrap_charm_deps()
unit-kata-1: 13:37:57 WARNING unit.kata/1.install File "/var/lib/juju/agents/unit-kata-1/charm/lib/charms/layer/basic.py", line 226, in bootstrap_charm_deps
unit-kata-1: 13:37:57 WARNING unit.kata/1.install check_call([pip, 'install', '-U', reinstall_flag, '--no-index',
unit-kata-1: 13:37:57 WARNING unit.kata/1.install File "/usr/lib/python3.8/subprocess.py", line 364, in check_call
unit-kata-1: 13:37:57 WARNING unit.kata/1.install raise CalledProcessError(retcode, cmd)
unit-kata-1: 13:37:57 WARNING unit.kata/1.install subprocess.CalledProcessError: Command '['/var/lib/juju/agents/unit-kata-1/.venv/bin/pip', 'install', '-U', '--force-reinstall', '--no-index', '--no-cache-dir', '-f', 'wheelhouse', 'netaddr==0.7.19', 'charms.reactive==1.5.2', 'pbr==5.11.1', 'charmhelpers==1.2.1', 'pyaml==21.10.1', 'urllib3==1.26.16', 'Jinja2==3.0.3', 'requests==2.27.1', 'certifi==2023.7.22', 'idna==3.4', 'Cython==0.29.36', 'PyYAML==5.3.1', 'charset-normalizer==2.0.12']' returned non-zero exit status 1.
unit-kata-1: 13:37:58 ERROR juju.worker.uniter.operation hook "install" (via explicit, bespoke hook script) failed: exit status 1
unit-kata-1: 13:37:58 INFO juju.worker.uniter awaiting error resolution for "install" hook