Change in behavior of extension loading in v1.11

[sethaxen]

Suppose I have a package A with an extension that depends on packages B and C. Package B also depends on C. On Julia v1.10, if I loaded packages A and B, the extension would be loaded. But on Julia v1.11, it seems that I must also explicitly load package C for the extension to be loaded.

I created a repo demonstrating this change in behavior: https://github.com/sethaxen/ExtensionsTestDemo.jl, where A=ExtensionTestDemo, B=StatsBase, C=Random. The tests check whether the extension is loaded depending on which dependencies are loaded, and the CI (e.g. https://github.com/sethaxen/ExtensionsTestDemo.jl/actions/runs/11652519441) demonstrates the change in behavior between v1.10 and v1.11.

[IanButterworth]

Duplicate of #56204 ?

[sethaxen]

Duplicate of #56204 ?

I'm not convinced it is. There the issue seems to be one extension trying to load another. That's not happening here.

[topolarity]

I can reproduce this on 1.11 but it appears to be resolved on nightly

I have a hunch this was probably fixed by #56234 (which is marked for 1.11 backport but hasn't been done yet)

[topolarity]

I can confirm this is fixed by #56658 (backport of the above)