emacs: handle specially-named tree-sitter grammars

[leungbk]

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Recent revisions of Emacs HEAD have a new markdown-ts-mode. This change allows Emacs to detect the markdown-inline grammar; to confirm, notice that on the latest nixpkgs, trying markdown-ts-mode will yield:

funcall-interactively: Cannot load language definition: not-found, "/nix/store/10zfcxcjk6f5w0m5va009yddr2m5rqf6-emacs-packages-deps/lib/libtree-sitter-markdown-inline: cannot open shared object file: No such file or directory", "/nix/store/10zfcxcjk6f5w0m5va009yddr2m5rqf6-emacs-packages-deps/lib/libtree-sitter-markdown-inline.0: cannot open shared object file: No such file or directory", "/nix/store/10zfcxcjk6f5w0m5va009yddr2m5rqf6-emacs-packages-deps/lib/libtree-sitter-markdown-inline.0.0: cannot open shared object file: No such file or directory", "/nix/store/10zfcxcjk6f5w0m5va009yddr2m5rqf6-emacs-packages-deps/lib/libtree-sitter-markdown-inline.so: cannot open shared object file: No such file or directory", "/nix/store/10zfcxcjk6f5w0m5va009yddr2m5rqf6-emacs-packages-deps/lib/libtree-sitter-markdown-inline.so.0: cannot open shared object file: No such file or directory", "/nix/store/10zfcxcjk6f5w0m5va009yddr2m5rqf6-emacs-packages-deps/lib/libtree-sitter-markdown-inline.so.0.0: cannot open shared object file: No such file or directory", "/home/brian/.config/emacs/tree-sitter/libtree-sitter-markdown-inline: cannot open shared object file: No such file or directory", "/home/brian/.config/emacs/tree-sitter/libtree-sitter-markdown-inline.0: cannot open shared object file: No such file or directory", "/home/brian/.config/emacs/tree-sitter/libtree-sitter-markdown-inline.0.0: cannot open shared object file: No such file or directory", "/home/brian/.config/emacs/tree-sitter/libtree-sitter-markdown-inline.so: cannot open shared object file: No such file or directory", "/home/brian/.config/emacs/tree-sitter/libtree-sitter-markdown-inline.so.0: cannot open shared object file: No such file or directory", "/home/brian/.config/emacs/tree-sitter/libtree-sitter-markdown-inline.so.0.0: cannot open shared object file: No such file or directory", "libtree-sitter-markdown-inline: cannot open shared object file: No such file or directory", "libtree-sitter-markdown-inline.0: cannot open shared object file: No such file or directory", "libtree-sitter-markdown-inline.0.0: cannot open shared object file: No such file or directory", "libtree-sitter-markdown-inline.so: cannot open shared object file: No such file or directory", "libtree-sitter-markdown-inline.so.0: cannot open shared object file: No such file or directory", "libtree-sitter-markdown-inline.so.0.0: cannot open shared object file: No such file or directory"

The underscores seem to be there solely to placate nvim-treesitter (4623212).

Fixes #348933.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 25.05 Release Notes (or backporting 24.11 and 25.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

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[jian-lin]

The underscores seem to be there solely to placate nvim-treesitter (4623212).

I do not think this commit has anything to do the issue this PR tries to solve because withPlugins modified by that PR is not used here.

This PR indeed works. However, it looks more like an upstream (Emacs or markdown_inline tree-sitter) issue. Can it be reproduced without Nixpkgs? If so, it is better to report this issue to upstream and have it fixed there.

[leungbk]

withPlugins modified by that PR is not used here.

OK, I don't think I explained the issue very well.

You're right that we're not using withPlugins here; my point in linking 4623212 was to stress that Neovim expects the LANG portion (and only that portion) of tree-sitter-LANG to have underscores instead of hyphens.

I should probably have linked #181195 (comment) instead, where language was explicitly set to be "markdown_inline" with an underscore (and not necessarily to placate Neovim).

I do not think this commit has anything to do the issue this PR tries to solve

In #348933, the OP noted However, some are missing, in particular libtree-sitter-markdown-inline.so does not appear., which this PR fixes; in the ls output he posted, he had only libmarkdown_inline.so (this since-merged #360388 would change that to libtree-sitter-markdown_inline.so, which would still not satisfy Emacs due to markdown-ts-mode's definition invoking (treesit-parser-create 'markdown-inline) with the hyphenated markdown-inline).

However, it looks more like an upstream (Emacs or markdown_inline tree-sitter) issue. Can it be reproduced without Nixpkgs?

The upstream naming markdown_inline seems to be intentional:

    {
      "name": "markdown_inline",
      "camelcase": "MarkdownInline",
      "scope": "text.markdown_inline",
      "path": "tree-sitter-markdown-inline",
      "highlights": "tree-sitter-markdown-inline/queries/highlights.scm",
      "injections": "tree-sitter-markdown-inline/queries/injections.scm",
      "external-files": [
        "common/common.js"
      ]
    }

For this reason, I would be hesitant to try and do something like changing our language name in nixpkgs from markdown_inline to something like markdown-inline.

The fact that Emacs expects the name libtree-sitter-markdown-inline.so with a hyphen instead of an underscore makes me suspect that Emacs users commonly install this grammar with a hyphen in its name, though I have evidence of this.

With all this in mind, do you currently prefer that we

a. go with something like the current PR or
b. ask Emacs upstream to invoke treesit-parser-create with the underscored name instead?

[jian-lin]

ask Emacs upstream to invoke treesit-parser-create with the underscored name instead

If it is indeed an upstream issue, i.e., it can be reproduced without Nixpkgs, then it would be good to report it to Emacs (and cc related people such as author of markdown-ts-mode and author of Emacs treesit infra).

go with something like the current PR

Even if it is an upstream issue, we probably should merge this PR now as a quick fix/workaround.

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Thanks for those links. They are very helpful for me knowing little about tree sitter to get an overview for this.

[nixpkgs-ci]

Successfully created backport PR for release-24.11:

• [Backport release-24.11] emacs: handle specially-named tree-sitter grammars #384572