• Emacs overlay for Nixpkgs ** Contents of the overlay

*** Elpa Daily generations of Elpa.

*** Melpa / Melpa stable Daily generations of Melpa & Melpa stable attribute sets.

*** EXWM & needed dependencies This overlay provides fresh versions of EXWM and dependencies. This is updated daily.

*** Emacs from Git and latest (including pre-releases) This overlay also provides two versions (latest from git) for Emacs. These are updated daily.

These attributes are named =emacsGit= and =emacsUnstable=. =emacsGit= is built from the latest =master= branch and =emacsUnstable= is built from the latest tag.

Emacs from git is not guaranteed stable and may break your setup at any time, if it breaks you get to keep both pieces.

The =feature/native-comp= branch is also provided under the attribute =emacsGcc=. This is to be considered highly experimental.

We also provide two attributes named =emacsGit-nox= and =emacsUnstable-nox= if you wish to have Emacs built without X dependencies, as well as the experimental pgtk branch which supports Wayland natively.

** Extra library functionality This overlay comes with extra functions to generate an Emacs closure from various types of dependency declaration. (These are abstractions on top of =emacsWithPackages=.)

For example, =emacsWithPackagesFromUsePackage= adds packages which are required in a user's config via =use-package= or =leaf=.

#+BEGIN_SRC nix { environment.systemPackages = [ (emacsWithPackagesFromUsePackage { # Your Emacs config file. Org mode babel files are also # supported. # NB: Config files cannot contain unicode characters, since # they're being parsed in nix, which lacks unicode # support. # config = ./emacs.org; config = ./emacs.el;

    # Package is optional, defaults to pkgs.emacs
    package = pkgs.emacsGit;

    # By default emacsWithPackagesFromUsePackage will only pull in
    # packages with `:ensure`, `:ensure t` or `:ensure <package name>`.
    # Setting `alwaysEnsure` to `true` emulates `use-package-always-ensure`
    # and pulls in all use-package references not explicitly disabled via
    # `:ensure nil` or `:disabled`.
    # Note that this is NOT recommended unless you've actually set
    # `use-package-always-ensure` to `t` in your config.
    alwaysEnsure = true;

    # For Org mode babel files, by default only code blocks with
    # `:tangle yes` are considered. Setting `alwaysTangle` to `true`
    # will include all code blocks missing the `:tangle` argument,
    # defaulting it to `yes`.
    # Note that this is NOT recommended unless you have something like
    # `#+PROPERTY: header-args:emacs-lisp :tangle yes` in your config,
    # which defaults `:tangle` to `yes`.
    alwaysTangle = true;

    # Optionally provide extra packages not in the configuration file.
    extraEmacsPackages = epkgs: [
      epkgs.cask
    ];

    # Optionally override derivations.
    override = epkgs: epkgs // {
      weechat = epkgs.melpaPackages.weechat.overrideAttrs(old: {
        patches = [ ./weechat-el.patch ];
      });
    };
  })
];

} #+END_SRC

Similarly, =emacsWithPackagesFromPackageRequires= adds packages which are declared in a =.el= package file's =Package-Requires= header, which can be handy for CI purposes:

#+BEGIN_SRC nix ... let emacsForCI = pkgs.emacsWithPackagesFromPackageRequires { packageElisp = builtins.readFile ./flycheck.el; extraEmacsPackages = epkgs: [ epkgs.package-lint ]; }; pkgs.mkShell { buildInputs = [ emacsForCI ]; } #+END_SRC

** Usage of the overlay *** Latest master each rebuild One way, and probably the most convenient way to pull in this overlay is by just fetching the tarball of latest master on rebuild.

This has side-effects if packages breaks or things like that you may want to be in control of which revision of the overlay you run.

Adding the overlay this way will extend your Emacs packages set to contain the latest EXWM and dependencies from their respective master and make the package =emacsGit= available. These of course change quite rapidly and will cause compilation time.

#+BEGIN_SRC nix { nixpkgs.overlays = [ (import (builtins.fetchTarball { url = https://github.com/nix-community/emacs-overlay/archive/master.tar.gz; })) ]; } #+END_SRC

*** Binary cache You will want to use the [[https://nix-community.org/#binary-cache][nix-community binary cache]]. Where the overlay's build artefacts are pushed. See [[https://app.cachix.org/cache/nix-community][here]] for installation instructions.

*** Install directly from the overlay The repository is meant to be used as an overlay as is explained above. Still, for experimental purposes, you might want to install a package directly from the overlay. For example, you can install =emacsGit= from a clone of this repository with the following command:

#+begin_src shell nix-build --expr 'with (import { overlays = [ (import ./.) ]; }); emacsGit' #+end_src

• Community

** IRC =#nixos-emacs= on =freenode=

** Nixpkgs issues

*** Emacs tracking issue https://github.com/NixOS/nixpkgs/issues/66303

LocalWords: EXWM NixOS emacsGit

LocalWords: SRC nixpkgs builtins fetchTarball url