Crawl registry (→ to rm restriction "Only works for pkgs in active project")

[tfiers]

exploration:

using Pkg

reg = Pkg.Registry.reachable_registries()[1]  # (first, and only, for me. the General)
pkgentry = values(reg.pkgs)[1]
p = Pkg.Registry.init_package_info!(pkgentry)

p.repo  # → https github url, to make svg dot nodes clickable :)
# in tooltip of svg dot nodes could go version or sth, mayb
p.deps  # weird format: map of versionrange (of what?) => set of deps (organized as name=>UUID map)
p.version_info  # useful ye. `first(keys(_))` is latest version i suppose

(from https://github.com/tfiers/julia-sketches, pkgdepgraph-v2)

[tfiers]

Do @infos: "Package found in active project, so we can use 'Manifest.toml'", stuff like that.
mayb if gathering deps (repeatedly calling that init_pkg_info!) is slow, then a line for each or sth

[tfiers]

First q: how to get uuid of pkg

ah, prob look at PkgDeps etc here

[tfiers]

https://github.com/JuliaEcosystem/PkgDeps.jl

https://github.com/JuliaEcosystem/PkgDeps.jl/blob/a568954/src/utilities.jl#L105:

• registry.pkgs[pkg_name].uuid

from https://github.com/JuliaEcosystem/PkgDeps.jl/blob/a568954/src/registry_instance.jl#L11

    d = parsefile(joinpath(path, "Registry.toml"))
    pkgs = Dict{AbstractString, PkgEntry}()

    for (uuid, info) in d["packages"]
        uuid = UUID(uuid)
        name = info["name"]
		…

[tfiers]

Pkg.Registry.reachable_registries()

so, their reachable_registries() (https://github.com/JuliaEcosystem/PkgDeps.jl/blob/a568954/src/PkgDeps.jl#L71) is not necessary. merged in base mayb.
mayb is necessary for 1.6

[tfiers]

hm, reg = only(Pkg.Registry.reachable_registries()) has a field name_to_uuids...
it's empty at start. there must be a fillin func somewhere

[tfiers]

just googled it, hah.
https://github.com/JuliaLang/Pkg.jl/blob/5ae866151e0cfd0536d0bfbb66e7f14ea026bd31/src/Registry/registry_instance.jl#L367-L370

function uuids_from_name(r::RegistryInstance, name::String)
    create_name_uuid_mapping!(r)
    return get(Vector{UUID}, r.name_to_uuids, name)
end

[tfiers]

Two files (both used by depgraph.jl):

• manifest.jl
• registry.jl

[tfiers]

This added a quirk: registry and Manifest may order packages differently, and that means dot renders something different:
with mani:

with registry:

(At least I think that's the reason for the difference)

This might cause user confusion.
Should be helped if "generated from [proj path]" or "generated from General registry" is in the

• graph label #65