Improve error messages for mis-matched nixpkgs release channel

[matthiasbeyer]

nixvim/plugins/lsp/language-servers/default.nix

Line 184 in c892aa2

(lib.map (

This line errors for me on main with unstable nixpkgs.

EDIT by maintainers

Asserting that pkgs was built from the expected nixpkgs release/channel may allow us to offer more useful error messages.

We could use lib.trivial.release (etc) to check for a compatible nixpkgs release.

We would probably need to track somewhere in our repo what release this branch is expecting though.

Maybe this could also be used within the docs to detect if the docs relate to stable or unstable nixivm? (see #2455)

[matthiasbeyer]

Okay, the issue here was that my nixvim flake input followed the unstable channel, but the nixvimModule got the stable channel passed as pkgs.

Maybe there should be a check for this?

[MattSturgeon]

Maybe there should be a check for this?

I can rename this issue to something like "assert that the expected nixpkgs release/channel is used"?

EDIT: done