This commit causes melpaBuild to use package-build from melpa/package-build
instead of melpa/melpa. Development of package-build happens in the former
repository whereas the latter is much larger, containing also the MELPA
recipes. We do not need to fetch the MELPA recipes from melpa/melpa, as we fetch
them one-by-one for Nixpkgs.
No real function change here, but this updates the trivial and melpa builders to
be formatted more consistently with the rest of the builders, and swaps
`eval "$preBuild"` for the more standard `runHook preBuild`.
package-build expects the recipe file name to match the Emacs package
name. `melpaBuild` takes an extra argument `ename` for the Emacs package
name (default: `pname`, the Nix package name) which is used to name the recipe
file.
Fixes: #43893
See also: #43609
All package sets are simultaneously updated to accommodate changes to
package-build. Due to new restrictions in package-build, all packages using
`melpaBuild` must now provide a recipe file, even those packages which are not
included in upstream MELPA.
Building packages requires package-build.el from Melpa, but installing
packages only requires package.el. Packages from ELPA are already built,
so there is no need to involve package-build.el.
When building a package from a Melpa recipe file, get the Emacs package
name from the recipe. Nix is more restrictive about packages names than
Emacs, so the Nix name for a package is sometimes different.
This simplifies melpa builder by merging with it my old emacs modes builder,
adds better instructions and support for overrides in emacs-packages.nix,
and renames some emacs-related stuff in all-packages.nix for sanity reasons.
I declare this backwards compatible since direct uses of emacsPackages in
configuration.nix are very unlikely.
