PDM can't update to prerelease branch

[bjdm]

Just been having a play around with getting DeclarativeBase ( #1140 ) to work properly and wanted to make my own branch to continue, however I'm running into an issue where pdm update --pre sqlalchemy will only install 1.4.45. I can't reproduce this with a bare pdm environment with only sqlalchemy ie. pdm init && pdm add --pre sqlalchemy and pdm init && pdm add sqlalchemy && pdm update --pre sqlalchemy both install/update to version 2.0.0b4.

Would anybody have any advice on how to best achieve this?

[bjdm]

Was able to get 2.0.0bx installed by performing the following:

pdm add pip
pdm run pip install -U --pre sqlalchemy
pdm remove pip

Should this be the method for using pdm and testing against the newer releases of sqlalchemy?