The only error seems to be:

Error: Can’t select database. We were able to connect to the database server (which means your username and password is okay) but not able to select the `wp_cli_test` database.

when trying to run wp db create.

The db command doesn't seem to be installed though. Shouldn't the error message be different then?

The nice thing is that the tests are now much more reliable and the failures are reproducible. So, now, a composer behat on local actually produces the same error. I'll investigate. I suppose it is the --verify of the config creation that fails because the db command errors out.

Ah makes sense.

I was so close to just require the db command like you just did now :-)

I tested first: