a new UUID is generated even if there is a Project.toml with an existing one

[tpapp]

Even if a package has a Project.toml with an uuid field, a new (apparently random, unrelated) one seems to be generated by the pipeline.

It would be nice to just use the existing one.

Cf discussion

[timziebart]

How is the process here? While certainly not being high-prio, it would be nice if it were solved.

[StefanKarpinski]

There is a solution: if you are registering a package in METADATA, then you should use the utility function Pkg.METADATA_compatible_uuid to generate a UUID for your project, e.g.:

julia> Pkg.METADATA_compatible_uuid("MyPkg")
UUID("793ebe2b-975c-555a-bd0c-65619c3a03ab")

[timziebart]

Oh, nice, thanks!

[tpapp]

I think the issue was closed a bit prematurely, for two reasons:

1. Pkg.METADATA_compatible_uuid is a workaround, not solution, and then it is not easily discoverable. A user could just set up a Project.toml by just reading the relevant manuals (Julia's docs, Pkg docs, etc) and never learn about it, running into the issue only when registering the package (and then it is pretty insidious, as mismatching UUIDs can give surprising behavior when one is unaware that this is a possibility).

2. I still don't understand why the registry has to do this. I understand that historically, packages had no UUIDs so one had to be generated, but that is becoming less and less common.

[StefanKarpinski]

The issue is in the wrong place, first off—there's no code here. Once we switch the registration process to registering directly with the General registry then this won't be an issue any more. So the solution to this problem is to implement JuliaLang/Pkg.jl#849.