Unclear error message when needing to precompile due to incompatible stacked environment

[Octogonapus]

Just wanted to record this from our discussion earlier.
When you have a stacked environment with a package in your default environment that's incompatible with your current environment, you get this unclear message:

(project env) pkg> precompile

julia> using GLMakie
[ Info: Precompiling GLMakie [e9467ef8-e4e7-5192-8a1a-b1aee30e663a] (cache misses: wrong source (4), incompatible header (2), mismatched flags (2))

This is made more confusing by ]precompile doing nothing.

I wouldn't want precompilation to switch into my default environment, but including something in the error message indicating this incompatibility would be helpful.

Julia 1.11.6.

[KristofferC]

but including something in the error message

which error message?

[IanButterworth]

We (I) added the (cache misses: wrong source (4), incompatible header (2), mismatched flags (2)) part thinking there was no valid reason to hit the old serial precompilation path, and I think that makes it look more like an error message now.

I do think it should show a message explaining why serial precompilation is needed.

[Octogonapus]

which error message?

Sorry the cache misses: wrong source looks like an error message, even though I guess it's not. What Ian said.

[IanButterworth]

Proposed solution here #59122