BLD: Clarify qtpy / pyqt dependencies

[tangkong]

Expected Behavior

our dependencies shouldn't be so confusing? Mabye? Should these be synced?

Current Behavior

• pcds-tag meta.yaml (this repo) has qtpy in test deps, but not run deps
• pcds-tag requirements.txt (this repo) has qtpy
• conda-forge has pyqt >=5 in run deps

Context

I was tagging and got confused again

Your Environment

pcds-5.7.3

[ZLLentz]

I think both recipes are technically wrong, making this confusing

I don't think a package with no direct e.g. PyQt5 imports should have pyqt in the run dependencies- isn't the point of using qtpy so that you can swap? (Separate discussion topic: does using qtpy even help anyone for packages like this?)

The CI would then of course need a way to pick pyqt, the test dependencies would be a reasonable place for this I think

The missing qtpy dependency here is clearly an error, even though it hasn't mattered because one of our dependencies has it as a dependency

[tangkong]

Your reasoning makes sense to me. So then appropriate changes would be:

• make meta.yaml match in both the feedstock and this repo
  • remove pyqt >=5 from run deps
  • add qtpy to run deps
  • add pyqt >=5 to test deps

[ZLLentz]

In addition to those, there's also some argument to made for adding pyqt >=5 to the run constrained dependencies (dependencies that can be missing, but if installed should have a constraint)

[klauer]

pyqt =5 is I thought what we settled on? PyQt6, if/when it gets up there, will almost assuredly be incompatible