Install hook failing when Octavia Charm is built originally built on Bionic/Focal/Impish

List of wheelhouse packages obtained from Xenial build (working)

List of wheelhouse packages obtained from Bionic build (failing)

List of wheelhouse packages obtained from Focal build (failing)

> As it is right now, it is impossible to build properly the charm Octavia on a environment more recent than Ubuntu Xenial.

Yes, this was intentional up to the last cycle. All the charms up to now were built on xenial as they all needed to support xenial (py35) and forward. However, the stable/21.10 charms are the last set that formally support xenial. The new "oldest" target is bionic/py36, as the next set of charms at least have to support bionic going forward.

One of the biggest issues is that almost none of the requirements.txt / test-requirements.txt / wheelhouse.txt work with the pip 21.x resolver. Everything is currently pinned to work with pip 20.3.2 which worked on py35 (xenial) as pip21 dropped support for py35.

We have a tranche of work coming up to switch to pip 21.x and move support to py36+ for all the charms, and for them to be built in charmhub/launchpad.

Please also note, that the tox.ini, requirements.txt, test-requirements.txt and src/test-requirements.txt are controlled centrally via the openstack-charmers/release-tools repo on github.com in order to keeps things aligned between the charms.

So that's just to provide a little bit of context as to "why we are where we are"!

For the moment, a workaround might be to launch a xenial LXD container/VM, install tox into it and build the charm there.

for the record, this is the command line I'm using to have a functional tox in Xenial

python3 -m pip install --user --upgrade 'filelock<3.3' 'pyparsing<3.0.0' 'tox==3.20' wheel 'packaging<21' 'setuptools<50.0.0' "pip<20.3" "virtualenv<20.0" "importlib-resources<3.0.0" "importlib-metadata<3.0.0" "pluggy<1.0.0"

This is because other dependencies have dropped python3.5 support.