Use Gleam version as a constraint in package resolution

[mine-tech-oficial]

As the title describes, allow package resolution to consider the gleam field in gleam.toml as a constraint check, so that when packages upgrade to a newer Gleam version, users of it aren't required to manually adjust its range

[giacomocavalieri]

Would this be a net positive? Wouldn't we want to encourage folks to always keep their gleam version up to date?

[mine-tech-oficial]

I would say that, if for some reason someone needs to support a specific version, they don't need to worry about bugs each time they update. An example (which is what, I suppose, quite some people stumbled on) was the (unofficial) Gleam Chess Tournament, as the code ran on container with Gleam v1.9.1.

[silby]

I would also have benefitted from this today. OpenBSD 7.7 has Gleam 1.9.1 in ports and OpenBSD ports/packages are only backported to the stable release in a somewhat ad hoc way/when there are security issues justifying the effort. I ran a package bump with Gleam 1.11.0 on my desktop but then had a compatibility issue with 1.9.1 on my server. I was able to tweak my manifest to fix it by constraining the package at issue.

[lpil]

@silby You must never edit the manifest. You should edit gleam.toml.

[silby]

Oh I see I was misleading. I induced a change in the manifest by editing gleam.toml. Clear communication eludes me this week.

[lpil]

Ah right! Thanks

[mtlynch]

This just bit me as well. I'm on NixOS, where the latest version of Gleam available is Gleam 1.10.0 even though the latest version is Gleam 1.11.0.

If I create a new project with gleam new, it pulls in a version of gleeunit that's incompatible with my version of Gleam:

$ gleam --version
gleam 1.10.0

$ gleam new --name myproject --skip-github .
Your Gleam project myproject has been successfully created.
The project can be compiled and tested by running these commands:

        gleam test
$ gleam run
  Resolving versions
Downloading packages
 Downloaded 2 packages in 0.01s
  Compiling gleam_stdlib
error: Incompatible Gleam version

The package `gleeunit` requires a Gleam version satisfying 1.11.0 <= v but you are using v1.10.0.

gleeunit 1.4.0 is correctly declaring its dependency on Gleam 1.11.0, so it would be helpful if gleam new considered that when choosing which version of gleeunit to pull in for a new project.

[manveru]

I was bit by the same issue, luckily NixOS/nixpkgs#407394 bumped Gleam to 1.11.0, but I think generally we should make use of the information that package maintainers provide to resolve versions properly.