Remove Pkg from dependencies

[sumiya11]

A PR for #1895.

I don't know if Base.get_pkgversion_from_path covers all the cases that were previously handled.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 87.24%. Comparing base (8fac1af) to head (0a401a3).
Report is 59 commits behind head on master.

Files with missing lines	Patch %	Lines
src/Nemo.jl	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1896      +/-   ##
==========================================
- Coverage   87.25%   87.24%   -0.01%     
==========================================
  Files          97       97              
  Lines       35655    35653       -2     
==========================================
- Hits        31111    31106       -5     
- Misses       4544     4547       +3     

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[lgoettgens]

This does not work on julia 1.6 (the compat bound of Nemo)

[sumiya11]

Would it be reasonable to do if VERSION < 1.11 then "old version()" else "new version()" end ?

EDIT: ah, no, the old version loads Pkg.

[lgoettgens]

Base.get_pkgversion_from_path is non-public, so shouldn't be relied on

[fingolfin]

If this was just about the Package version, we could use the Compat package and then Compat.pkgversion(Nemo).

However this code also tries to determine if one is using a dev version, i.e., whether it is being run from a git clone. Alas the code for doing that is buggy already (it checks whether /dev/ is in the path, which is OK if someone used Pkg.develop but not for people like me who manually git clone repositories).

Interestingly Nemo.versioninfo tries to get a more thorough git status, but it is also broken (at least with Julia 1.10 and 1.11)

julia> Nemo.versioninfo()
Nemo version 0.47.1
Nemo: ERROR: UndefVarError: `LibGit2` not defined in `Base`

[fingolfin]

In Oscar.jl we instead use this code to determine if it is a dev version (but this is also far from perfect -- and it uses Pkg):

const is_dev = (function()
        deps = Pkg.dependencies()
        if Base.haskey(deps, PROJECT_UUID)
          if deps[PROJECT_UUID].is_tracking_path
            return true
          end
        end
        return occursin("-dev", lowercase(string(VERSION_NUMBER)))
    end)()

[sumiya11]

I see, thank you for explanation.

In case deps contains the uuid key, are ver.source and pkgdir the same (pkgdir defined in src/Nemo.jl)? If so, this case could be covered without Pkg, modulo bugs with /dev/.

Otherwise, when deps contains no uuid key, is version() == "building" equivalent to Base.active_project() == pkgdir (up to appending "/Project.toml" to pkgdir) "?

[fingolfin]

@sumiya11 I have no idea and in any case, none of this is documented AFAIK. I am not concerned with imitating current behavior 1-1. Rather, the general idea, which is to be able to detect reliably which version a user reporting an issue really is using: i.e. either a specific stable release, and which; or some git version (ideally identified by commit). Just like the Julia banner does (perhaps one could look at its current code for inspiration).

[fingolfin]

To be clear: In general I would be very happy if we could drop the dependency on Pkg, so I approve with the general direction of this PR, but details need to be sorted out. Thank you for raising this issue!

[sumiya11]

I am not concerned with imitating current behavior 1-1. Rather, the general idea, which is to be able to detect reliably which version a user reporting an issue really is using: i.e. either a specific stable release, and which; or some git version (ideally identified by commit). Just like the Julia banner does (perhaps one could look at its current code for inspiration).

Thank you for the clarification.

If so, why not ask the user for the output of Pkg.status() instead of relying on the error-prone version ?

[thofma]

It is mainly for the banner which includes the version number. Maybe they fix the Pkg loading regression in 1.11.1. It is not the only thing that got slower.