It seems that poetry comes installed with CCI python convenience image now. But the installation method used doesn’t allow certain features of poetry. For example I have a job that needs the 1.x alpha of poetry (for its export sub-command, for serverless) but its not Just Working ™:
circleci@b77ae58a319d:~/project$ poetry self:update --preview [RuntimeError] Poetry was not installed with the recommended installer. Cannot update automatically. self:update [--preview] [--] [<version>]
Now I have to resort to pip, then deal with sudo, yatta yatta.