Issues building Kolla images with recent versions of Python requests

If you find yourself having issues building Kolla docker container images with errors like this:

INFO:kolla.common.utils:Using engine: docker
INFO:kolla.common.utils:Found the container image folder at /home/mikal/src/kerbside-patches/venv-stable/2023.1-patches/share/kolla/docker
ERROR:kolla.common.utils:Unable to connect to container engine daemon, exiting
INFO:kolla.common.utils:Exception caught: Error while fetching server API version: Not supported URL scheme http+docker

It is likely that you’re running a recent version of requests which has an unresolved issue. Try downgrading requests manually, like this:

$ ...venvpath.../bin/pip install requests==2.31.0
Collecting requests==2.31.0
  Downloading requests-2.31.0-py3-none-any.whl (62 kB)
...snip...
Successfully installed requests-2.31.0

Thanks for this stack overflow post for the pointer.