Support different versions of packages for different environments about pdm-backend

[frostming]

Another option would be to support multiple lock files which could manage different environments: Essentially use pdm.lock for local development and a pdm.prod.lock for production deployments.

https://pdm-project.org/en/stable/usage/lockfile/#specify-another-lock-file-to-use

[mezuzza]

Thanks for the pointer. I misunderstood the intention for that feature, but the reason I originally rejected it in my head was that it's not guaranteed that the lock file will be kept in sync.

Is the expectation that you can use pdm lock --update-reuse-installed -L pdm.prod.lock? That seems a bit error prone, but we'll probably make do if that's required.