Given that Emacs 29 is considered beta, it will not be aliased to `emacs`.
And, given that Emacs 29 ships with Pure GTK feature, why not to make it
available?
A list of modifications:
- The calling handles at `top-level/all-packages.nix` were transferred to
`pkgs/applications/editors/emacs/default.nix` (the good old `recurseIntoAttrs`
design pattern);
- The files `macport.nix` and `28.nix` were removed, replaced by the bigger and
better `sources.nix`;
- Aliases for the most important derivations were put on `all-packages.nix`;
- The file `generic.nix` was refactored. Among its changes, the most noticeable:
- `pname` is decorated according to the selected UI options;
- Environment variables are explicitly under `env` set;
- The `null` defaults and (in)equality tests were removed;
- It obliged the addition of some Boolean flag guards;
- The flag `noGui` was added, allowing easier override for `emacs-nox`.
With this huge refactor, the emacs build functions become more sane and
maintainable, allowing future additions.
The Nix-driven bootstrap of gcc resulted in some changes to the
structure of the `libgccjit` outpaths, and also added an additional
output (`libgcc`) to `gcc`.
This commit makes the corresponding changes in the `emacs`
derivation in order to not break emacs.
Emacs is the only user of `libgccjit` in nixpkgs at the moment.
The version of project on ELPA has now moved well beyond what was
available in emacs 28, and packages such as eglot are depending on
these newer versions.
This commit adds basic support for tree-sitter in the emacs build,
such that (if the user opts into tree-sitter support), tree-sitter
will be enabled and binary library files for tree-sitter can be
included in the `lib` directory of packages passed to
`emacsWithPackages`. The libraries will be aggregated and included in
treesit-extra-load-path.
The previous pattern for this in the community was to add tree-sitter
libaries by patching emacs's `RUNPATH` with `patchelf` in a post-fixup
phase. However, this has the substantial drawback that two different
emacs installations with different lists of available tree-sitter
libraries must be entirely separate builds. By supplying the
tree-sitter libraries in the wrapping layer of `emacsWithpackages`, it
becomes possible to share a single, more-cacheable "core emacs".
This support defaults to "on" only in emacs 29 and up, since previous
versions do not support tree-sitter out of the box.
