neovim, neovimUtils, neovim-qt: drop python2 support

[mweinelt]

Motivation for this change

In 2a00e53 pynvim support for python2 was disabled, this broke the
neovim build. I really think it is time to let go of python2 support in
neovim.

Fixes the build for me, I have no regrets.

I'm aware we might need a release notes entry for that. I'm open to suggestions, I've never relied on python2 in neovim.

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)

  /nix/store/synllhwl09qs1jzg9v452npvbgq6y0pf-neovim-0.4.4	  425376328
  /nix/store/zapccq0qrj4k5b94j49ifnqy6i5mzxkx-neovim-0.4.4	  383572776
  

• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[mweinelt]

Drive-by cleanup of inputs, not used since 3a25004.

[teto]

it's a bit annoying to break compatibility inside the same neovim release (python2 is dropped in 0.5) but I am not aware of any python2 remote plugins so it should probably be fine ?

[teto]

maybe add some warning if python2 is used since it's a breaking change for the same version so it can be surprising.

[mweinelt]

maybe add some warning if python2 is used since it's a breaking change for the same version so it can be surprising.

Sounds great, though not sure where would be a good spot.

[teto]

when withPython2 is used, add a lib.warn or even a throw with the appropriate message.

[mweinelt]

I've added three asserts/throws, can you check whether that is sufficient?

Also extended the release notes for vims python2 support drop with neovim.

Both as fixups, will squash them before merge.

[teto]

Looks good to me

[austinbutler]

Hopefully this is just me doing it wrong, but I can't seem to get this to work in my home-manager config.

{
  programs.neovim = {
    enable = true;
    package = (import (builtins.fetchTarball {
      url =
        "https://github.com/mweinelt/nixpkgs/archive/b91ddf1960e1c825a9bcddcbfa67d4eae0e1b971.tar.gz";
      sha256 = "0jdw4j0r6fkqhqaac5gr4i5nq35pm49wh98idzckrzhsg5h1b7yn";
    }) { config = { allowUnfree = true; }; }).neovim-unwrapped;
    extraConfig = ''
      if (has("nvim"))
        "For Neovim 0.1.3 and 0.1.4 < https://github.com/neovim/neovim/pull/2198 >
        let $NVIM_TUI_ENABLE_TRUE_COLOR=1
      endif

      "For Neovim > 0.1.5 and Vim > patch 7.4.1799 < https://github.com/vim/vim/commit/61be73bb0f965a895bfb064ea3e55476ac175162 >
      "Based on Vim patch 7.4.1770 (`guicolors` option) < https://github.com/vim/vim/commit/8a633e3427b47286869aa4b96f2bfc1fe65b25cd >
      " < https://github.com/neovim/neovim/wiki/Following-HEAD#20160511 >
      if (has("termguicolors"))
        set termguicolors
      endif

      filetype plugin indent on
      syntax on
      set tabstop=4 shiftwidth=4 expandtab
      set clipboard+=unnamedplus
    '';
    extraPython3Packages = (ps: with ps; [ black isort pylint ]);
    plugins = with pkgs.vimPlugins; [
      vim-nix
      coc-nvim
      coc-css
      coc-explorer
      coc-git
      coc-go
      coc-html
      coc-json
      coc-prettier
      coc-pyright
      coc-rust-analyzer
      coc-tsserver
      coc-yaml
      {
        plugin = vim-autoformat;
        # https://github.com/Chiel92/vim-autoformat/blob/master/plugin/defaults.vim
        config = ''
          let g:formatters_javascript = ['prettier']
          let g:formatters_json = ['prettier']
          let g:formatters_python = ['black']
          let g:formatters_typescript = ['prettier']
          let g:formatters_yaml = ['prettier']
        '';
      }
      {
        plugin = vim-one;
        config = ''
          set background=dark
          colorscheme one
        '';
      }
      vim-lastplace
    ];
    viAlias = true;
    vimAlias = true;
    vimdiffAlias = true;
    withNodeJs = true;
    withPython3 = true;
  };
}

I still end up with:

unpacking channels...
error: pynvim-0.4.3 not supported for interpreter python2.7
(use '--show-trace' to show detailed location information)

It seems it should be using the package from your branch since it checks the sha256.

[mweinelt]

The only pynvim occurrence that are left are scoped with python3.pkgs or python3Packages, so I guess you are not using the matching utils or wrapper from this branch.

Squashing now.

[teto]

@SCOTT-HAMILTON does this PR work for you ?

[austinbutler]

Was able to get it working once I realized home-manager calls wrapNeovimUnstable, I then created an overlay for that package instead. Sorry for the noise, but I can confirm this works for me now.