do not run i/o when precompiling

[t-bltg]

Fix issue when precompiling extensions:

This means that a package has started a background task or event source that has not finished running. For precompilation to complete successfully, the event source needs to be closed explicitly. See the developer documentation on fixing precompilation hangs for more help.

A version bump would be appreciated.

Needed for JuliaPlots/Plots.jl#4904.

[mbaz]

Thanks for the PR. This issue has been fixed in the dev branch (which will become v2.0), but a version bump in v1 is a good idea. I'll need to take a look at the test failures, but I'll try to get this done soon.

[t-bltg]

Would it be possible to release a fix quickly for 1 ?

This is currently deadlocking CI (as in https://github.com/JuliaPlots/Plots.jl/actions/runs/8514690332/job/23320875036?pr=4914#step:9:667).

Thanks.

[mbaz]

I understand the urgency. I'll fix this and release ASAP.

[mbaz]

v1.1.1 has been released. Let me know if any issues come up.

[t-bltg]

@mbaz, thanks, but the proposed fix doesn't work in 1.1.1:

Gaston.jl/src/Gaston.jl

Line 94 in c7fe06a

code = success(`gnuplot --version`)

is causing the same message as in #185 (comment).

The recommended way is to use ccall(:jl_generating_output, Cint, ()) == 1 && return as implemented in this PR.
Please explain what's wrong with this proposition ?

[mbaz]

Sorry about that. What version of Julia did you use to test? I tested on v1.6 and 1.10 and I don't see that message.

Anyway, I have a more radical solution that should definitely solve this. I'll need a couple of days to implement it and cut a new release.

[t-bltg]

This is on linux, julia 1.10.2, and this deadlock appears when precompiling the GastonExt from PlotsBase in the v2 branch.

[mbaz]

Interesting; I'm on Linux and 1.10.2 myself.

Is it possible for you to test using a branch (or a tag) on this repo, or do you need a release?

[t-bltg]

We would need a new release since this is affecting CI: see for example https://github.com/JuliaPlots/Plots.jl/actions/runs/8514690332/job/23320875036?pr=4914#step:9:667 where Gaston is clearly incriminated for the deadlock.

[t-bltg]

And locally, ccall(:jl_generating_output, Cint, ()) == 1 && return works.

[mbaz]

v1.1.2 has been released -- please let me know how it goes.

[t-bltg]

Thanks, it works, CI seems to go past precompilation now ...