beam-packages: init elixir_ls 0.7.0

[happysalada]

Motivation for this change

add elixir_ls to nixpkgs

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

additional context

This is pretty much copyPasta from https://github.com/hauleth/nix-elixir/blob/master/lib/elixir-ls.nix

@minijackson @hauleth @NobbZ @afontaine @balsoft @yurrriq @cw789 you might be interested in this

[balsoft]

Since this is just copying someone else's code, wouldn't it need a copyright notice as required by the license?

[minijackson]

Damn, and here I wanted to be the first one to package something with the new mixRelease ^^

The project builds, and runs fine. Tested with NixOS and LanguageClient-neovim. I haven't tested the debugger, since I don't have a VS code installation.

One weird thing is that nix-review doesn't detect a change in packages, and so builds nothing. This might have to do with beamPackages not being recognized as a "Package Set" (example).

Since this is just copying someone else's code, wouldn't it need a copyright notice as required by the license?

Another possibility would be to ask the original developer for his explicit permission. I also think a mention of its origins in a comment would be nice. I don't think recall having a precedent in nixpkgs where the derivation code mentions its previous license.

Now, I am not a lawyer, but Nixpkgs is also licensed under MIT, with a copyright to edolstra and Nixpkgs/NixOS contributors, and it seems @hauleth has contributed to Nixpkgs, so the Nixpkgs license should be a superset of the one from @hauleth's repository? But I think it's still better to have his explicit permission.

[happysalada]

more than happy to include anything @hauleth judges appropriate.
Everytime I interacted with him though, he has been forward about not caring about attribution.
Since he might not be available, perhaps I can add a TODO comment about attribution and whenever he comes forward we can rectify that? Just a thought to get this merged to provide value to other people faster.

@minijackson This one doesn't count, it's just a copy paste. You can still be the first one that packages something original! :-)

Also regarding the nixpkgs-review I've added elixir_ls to all_packages, it looks like it's working

[SuperSandro2000]

One weird thing is that nix-review doesn't detect a change in packages, and so builds nothing. This might have to do with beamPackages not being recognized as a "Package Set" (example).

That needs fixing rather sooner than later because ofborg does not detect eval errors in this case.

Now, I am not a lawyer, but Nixpkgs is also licensed under MIT, with a copyright to edolstra and Nixpkgs/NixOS contributors, and it seems @hauleth has contributed to Nixpkgs, so the Nixpkgs license should be a superset of the one from @hauleth's repository? But I think it's still better to have his explicit permission.

Since he might not be available, perhaps I can add a TODO comment about attribution and whenever he comes forward we can rectify that?

Adding him to the commit as an author is enough. His code is also licensed under MIT.

[SuperSandro2000]

This should be done automatically for all packages because we don't want to maintain a list of packages here.

[happysalada]

I've added the suggested fix. Since it was adding some other packages on top, I've removed those.
Waiting for the build to check.

[happysalada]

I ran into an interesting problem here.
You can recursively add packages, that was not a problem.
The solution looked something like

beam = (let
   packages = callPackage ./beam-packages.nix { };
   interpreters = packages.interpreters;
in 
   packages // removeAttrs interpreters [ "lfe" "lfe_1_2" "lfe_1_3" ]);

However you still need to inherit those. I haven't found a way to recursively inherit something.
So unless I am missing something, we need to keep the current syntax

[SuperSandro2000]

I think you need to use passthru in the packages for those attributes.

[happysalada]

I have opened a separate issue for this
#119201
just so that it doesn't block this PR.

[happysalada]

Result of nixpkgs-review pr 118950 run on x86_64-darwin 1

1 package built:

• elixir_ls

[afontaine]

Result of nixpkgs-review pr 118950 run on x86_64-linux 1

1 package built:

• elixir_ls

[happysalada]

Regarding contribution, if I added a message in the commit saying something like

taken from code written by github.com/hauleth

Would that work for you @balsoft ?
Or perhaps including the full source of the code?

[balsoft]

It's not up to me to decide, ask @hauleth .

[happysalada]

sure, I would say let's leave it like this for a week and we can try to think of an intermediate solution if there is no feedback.

[hauleth]

@balsoft @happysalada You can just add comment on top

Based on work of Hauleth

And it will be enough for me

[happysalada]

@hauleth thanks for your feedback! Btw I'm going to leave the erlang_ls, if you are interested in adding it, I'm sure @balsoft would be happy to help you merge it.
I've added the attribution, plus a little sentence of mine :-)

@balsoft let me know if you feels it needs anything else.

[happysalada]

I'm planning on leaving this open until next monday 19th of April.
Please feel free to comment on anything you think I overlooked.

[Br1ght0ne]

Thanks a lot @happysalada, @hauleth and everyone else - I tried to add this a long time ago, and it's a pleasure to see a good PR. Waiting for April 19th