Default :tk pygui makes julia registry segfault

[mloubout]

I've spent a few days trying to figure out what's wrong without success, but it looks like the default PythonPlot backend (:tk) is making import segfault at least in julia automerge CI:

https://github.com/JuliaRegistries/General/actions/runs/11556341068/job/32163801717?pr=117989#step:17:863

I wanted to change the default backend but from the look of it here it would need PyCall which defeat the purpose of using PythonPlot in the first place.

If the backend could be handled via preferences or environment variable so that it can be set before PythonCall is imported it would be quite helpful.

[stevengj]

Sorry, the instructions were mis-copied over from PyPlot.jl … you don't use PyCall for this. Just set the MPLBACKEND environment variable.

Fixed in 93dfb2e