Add deprecation notice on using

[Seelengrab]

This adds a deprecation notice that will be printed on using Formatting, to inform users that the package has been deprecated and that they should consider using a different package.

This is intended to be released in conjunction with #111. This will also need a release to General, since it bumps the version.

[kescobo]

If there are people using this package, and don't need additional support / features, does this have any ongoing runtime cost?

Also, is it going to show up if this is an indirect dependency of something that I use?

[Seelengrab]

If there are people using this package, and don't need additional support / features, does this have any ongoing runtime cost?

No, this is only printed during using through __init__. All packages added there are part of the sysimage or are stdlibs already, highly likely to be loaded already. I guess it could be moved to precompilation too?

I'm mostly concerned with people using this package assuming that it works, when it evidently has fatal flaws, such as #108, which prints completely wrong results. Whoever is using this package and trusting its output might be in for a rude awakening.

Also, is it going to show up if this is an indirect dependency of something that I use?

Possibly? If so, we can add a marker that this is specifically for Formatting.jl, since the current message doesn't specify. Good catch, thank you! I'll try it out.

[Seelengrab]

Ok, with packages of a dependency chain like Baz -> Foobar -> Formatting.jl I get this output on 1.0.5:

and this on 1.11+:

so unfortunately, __init__ won't work for these purposes, since I can't seem to get it to print something on earlier versions. The logging message does make it clear that it's originating from Formatting, so I guess I can add a note directing the user to check ]why Formatting to find out which dependency they have to report this upstream issue to:

The downside is that this has only been supported since 1.9...

[kescobo]

The downside is that this has only been supported since 1.9...

I'm fine with that for something like this that's usability - focused.

[kescobo]

I get this output on 1.0.5:

If people are using exceptionally old Julia releases, frankly they should expect that lots of what they use is deprecated/ unmaintained.

Ideally, it would work at least with LTS, but even if it's only on the current release, I'd prefer it being in __init__ so we're not spamming people where it's an indirect dep every time they load a package

[MasonProtter]

JuliaHub says this has 81 direct dependants and 666 indirect dependants, so yeah we need to be kinda careful about not overzealously spamming people.

I would suggest putting it in an if ccall(:jl_generating_output, Cint, ()) == 1 block or something

[Seelengrab]

If people are using exceptionally old Julia releases, frankly they should expect that lots of what they use is deprecated/ unmaintained.

Yeah, unfortunately the precompilation printing is only available with 1.11, it doesn't work with LTS. Even if 1.10 is the next LTS, it won't show up until the next LTS after that for everyone bound to LTS.

I could add one-time printing into the constructor of FormatSpec, which probably catches everyone that uses the package. I guess that would break any and all printing that assumes it just works though.

I would suggest putting it in an if precompiling_output block or something

This package has compats back to 1.0, is there a version of that that goes that far back? Kinda bad that there's no CI set up here :/

[MasonProtter]

Seems to work on v1.0:

mason:~$ julia +1.0 -q --startup=no
julia> ccall(:jl_generating_output, Cint, ())
0

[MasonProtter]

mason:~$ cat Foo/src/Foo.jl
module Foo

if ccall(:jl_generating_output, Cint, ()) == 1
    println("hellllllo!")
end

end # module

mason:~$ julia +1.0 -q --startup=no
julia> using Foo
hellllllo!

julia> exit()

mprotter@dirac:~$ julia +1.0 -q --startup=no
julia> using Foo

julia> exit()

[Seelengrab]

Hmm.. I've added another dependency to the fake chain, ala Baba -> Baz -> Foobar -> Formatting and if I nuke the packages from .julia/compiled, I truly do get triple the output if it's in __init__, even if it's wrapped in jl_generating_output:

which is way too much. This needs a better solution :(

[Seelengrab]

Precompilation wipes the slate clean when it comes to global state, so I can't even really cache this properly, right? Seems like this will have to be hacked into some other place, perhaps the constructor here would be a good candidate? This will delay printing the warning until the first time someone formats something, but at least it'll only be to stderr. The upside is that this will work on all currently supported versions, so it has the biggest reach.

[MasonProtter]

the generating_output thing shouldn't be in init, it should be toplevel in the package.

[Seelengrab]

That did the trick! This really should be documented & made official. Only shows up on <1.11 when having Formatting.jl as a direct dependency, but oh well. All is good on 1.11 now!

[MasonProtter]

Yeah I only learned that trick by @macroexpanding PrecompileTools.@compile_workload

[kescobo]

@Seelengrab I can't get to this right now, but please feel free to ping me again if I haven't taken care of it by Monday

[Seelengrab]

Will do!

[Seelengrab]

Thanks @kescobo!