Add log message for __precompile__(false)

[NHDaly]

Add a log message that we're bailing on precompilation because we encountered __precompile__(false).

Also states that we're importing the package the "normal way" to help explain why this can still be slow.

Opened in response to #29467.

[NHDaly]

This isn't a perfect solution; ideally we would never print Precompiling $pkg at all, but it's not possible to know whether we'll end up finding a __precompile__(false) statement somewhere in the package until we've already finished precompiling!

So I think this is a decent workaround -- just letting the user know what's happening: 1. we've bailed on precompilation, and 2. now we're gonna import the package the regular way.

Help bikeshedding on the exact wording of this log message would be appreciated. :) Thanks!

[NHDaly]

@KristofferC can i bug you for a review of this? I'm just going back to clean up old PRs. :)

It's a small logging change, but i think a good usability improvement!

[KristofferC]

Seems better than the status quo so if you have verified that it works correctly, LGTM.

[NHDaly]

so if you have verified that it works correctly, LGTM.

Yes, it seems to work locally.

pkg> add StatPlots#v0.8.1
...

julia> using StatPlots
[ Info: Precompiling StatPlots [60ddc479-9b66-56df-82fc-76a74619b69c]
[ Info: Skipping precompilation since __precompile__(false). Importing StatPlots [60ddc479-9b66-56df-82fc-76a74619b69c].

julia> using StatPlots

julia>

And then the second time after restarting julia:

julia> using StatPlots
[ Info: Recompiling stale cache file /Users/nathan.daly/.julia/compiled/v1.2/StatPlots/iAmZm.ji for StatPlots [60ddc479-9b66-56df-82fc-76a74619b69c]
[ Info: Skipping precompilation since __precompile__(false). Importing StatPlots [60ddc479-9b66-56df-82fc-76a74619b69c].

It's better than nothing, and at least it gives you an understanding of why it's taking so long! :)

Thanks for the review.

[NHDaly]

Please take another look: I merged in the latest master, and the build now passes. :)

I think this is good to merge, and would be a useful change to prevent further confusion. :)

[KristofferC]

Thanks for the work here!

[NHDaly]

Thanks for the review, @KristofferC! :)