My personal hacked together script for building a completely self-contained Emacs.app application on macOS, from any git branch, tag, or ref. With support for native-compilation.
Use this script at your own risk.
- To use new features available from master or branches, which have not made it into a official stable release yet.
- Homebrew builds of Emacs are not self-contained applications, making it very difficult when doing HEAD builds and you need to rollback to a earlier version.
- Both Homebrew HEAD builds, and nightly builds from emacsformacosx.com are
built from the
master
branch. This script allows you to choose any branch, tag, or git ref you want.
Nightly and stable binary builds produced with this build script are available from jimeh/emacs-builds.
The build produced does have some limitations:
- It is not a universal application. The CPU architecture of the built application will be that of the machine it was built on.
- The minimum required macOS version of the built application will be the same as that of the machine it was built on.
- The application is not signed automatically, but the CLI tool used to sign the
nightly builds is available. Run
go run ./cmd/emacs-builder package --help
for details. More detailed instructions will come soon.
Required with both Nix and Homebrew approaches:
The Nix package manager is the preferred and most reliable way to install all dependencies required to build Emacs, by way of a Nix flake included in the project root.
To install all required dependencies within the nix shell, run:
nix develop --command make bootstrap
If you do not have Nix installed, then the alternative way to manage and install build-time dependencies is via Homebrew.
Ruby 3.3.x or later is also needed to execute the build script. Earlier versions may work, but are untested. Simplest way to install a recent Ruby version is via Homebrew:
brew install ruby
And finally, to install all built-time dependencies, run:
make bootstrap
As of writing (2024-11-30) it works for me on my machine and for the nightly builds in jimeh/emacs-builds. Your luck may vary.
I have successfully built:
emacs-29.4
release tag.emacs-30.0.92
pretest tag.master
branch (Emacs 31.x).
For reference, my machine is:
- 14-inch MacBook Pro (2023), Apple M3 Max (16-cores)
- macOS Sonoma 15.1.1 (24B91)
- Xcode 16.1 (16B40)
The nightly builds are built with
GitHub Actions on GitHub-hosted runners, using macos-13
for Intel builds, and
macos-14
for Apple Silicon builds. The build environment is managed with Nix,
and targets the macOS 11 SDK.
Ensure Flakes are enabled, and enter the flake
development environment with nix develop
. Within this environment, you can
execute the ./build-emacs-for-macos --help
to get started.
Or you can run the build script via nix develop
:
nix develop --command ./build-emacs-for-macos --help
The Nix environment defaults to targeting the macOS 11 SDK, which makes Emacs
builds compatible with macOS 11.3 or later. You can easily target later macOS
SDKs. Versions 11 to 15 are available. For example, to target the macOS 12 SDK,
run nix develop .#macos12
Run make boostrap
to ensure all Ruby and Homebrew dependencies are installed.
Usage: ./build-emacs-for-macos [options] <branch/tag/sha>
Branch, tag, and SHA are from the emacs-mirror/emacs/emacs Github repo,
available here: https://github.com/emacs-mirror/emacs
Options:
--info Print environment info and detected library paths, then exit
--preview Print preview details about build and exit.
-j, --parallel COUNT Compile using COUNT parallel processes (detected: 16)
--git-sha SHA Override detected git SHA of specified branch allowing builds of old commits
--[no-]use-nix Use Nix instead of Homebrew to find dependencies (default: enabled if IN_NIX_SHELL is set)
--[no-]tree-sitter Enable/disable tree-sitter if supported (default: enabled)
--[no-]native-comp Enable/disable native-comp (default: enabled if supported)
--optimize Shorthand for --native-march --native-mtune --fomit-frame-pointer (default: disabled)
--[no-]native-march Enable/disable -march=native CFLAG (default: disabled)
--[no-]native-mtune Enable/disable -mtune=native CFLAG (default: disabled)
--[no-]fomit-frame-pointer Enable/disable -fomit-frame-pointer CFLAG (default: disabled)
--[no-]native-full-aot Enable/disable NATIVE_FULL_AOT / Ahead of Time compilation (default: disabled)
--[no-]relink-eln-files Enable/disable re-linking shared libraries in bundled *.eln files (default: enabled)
--[no-]rsvg Enable/disable SVG image support via librsvg (default: enabled)
--[no-]dbus Enable/disable dbus support (default: enabled)
--[no-]alpha-background Enable/disable experimental alpha-background patch when building Emacs 30.x - 31.x (default: disabled)
--no-frame-refocus Apply no-frame-refocus patch when building Emacs 27.x - 31.x (default: disabled)
--no-titlebar Apply no-titlebar patch when building Emacs 27.x - 28.x (default: disabled)
--[no-]xwidgets Enable/disable XWidgets when building Emacs 27.x (default: disabled)
--[no-]poll Apply poll patch (deprecated)
--posix-spawn Apply posix-spawn patch (deprecated)
-p, --patch=URL Specify a custom patch file or URL to apply to the Emacs source (can be used multiple times)
--[no-]fd-setsize SIZE Set an file descriptor (max open files) limit (default: 10000)
--github-src-repo REPO Specify a GitHub repo to download source tarballs from (default: emacs-mirror/emacs)
--[no-]github-auth Make authenticated GitHub API requests if GITHUB_TOKEN environment variable is set.(default: enabled)
--work-dir DIR Specify a working directory where tarballs, sources, and builds will be stored and worked with
-o, --output DIR Output directory for finished builds (default: <work-dir>/builds)
--build-name NAME Override generated build name
--dist-include x,y,z List of extra files to copy from Emacs source into build folder/archive (default: COPYING)
--[no-]self-sign Enable/disable self-signing of Emacs.app (default: enabled)
--[no-]archive Enable/disable creating *.tbz archive (default: enabled)
--[no-]archive-keep-build-dir
Enable/disable keeping source folder for archive (default: disabled)
--log-level LEVEL Build script log level (default: info)
--plan FILE Follow given plan file, instead of using given git ref/sha
Resulting applications are saved to the builds
directory in a bzip2 compressed
tarball.
If you don't want the build process to eat all your CPU cores, pass in a -j
value of how many CPU cores you want it to use.
Re-building the same Git SHA again can yield weird results unless you first
trash the corresponding directory from the sources
directory.
To download a tarball of the master
branch (Emacs 28.x with native-compilation
as of writing) and build Emacs.app from it:
./build-emacs-for-macos
To build the stable emacs-29.4
release git tag run:
./build-emacs-for-macos emacs-29.4
All sources as downloaded as tarballs from the emacs-mirror GitHub repository. Hence to get a list of tags/branches available to install, simply check said repository.
Builds come with a custom emacs
shell script launcher for use from the command
line, located next to emacsclient
in Emacs.app/Contents/MacOS/bin
.
The custom emacs
script makes sure to use the main
Emacs.app/Contents/MacOS/Emacs
executable from the correct path, ensuring it
finds all the relevant dependencies within the Emacs.app bundle, regardless of
it it's exposed via PATH
or symlinked to from elsewhere.
To use it, simply add Emacs.app/Contents/MacOS/bin
to your PATH
. For
example, if you place Emacs.app in /Applications
:
if [ -d "/Applications/Emacs.app/Contents/MacOS/bin" ]; then
export PATH="/Applications/Emacs.app/Contents/MacOS/bin:$PATH"
alias emacs="emacs -nw" # Always launch "emacs" in terminal mode.
fi
If you want emacs
in your terminal to launch a GUI instance of Emacs, don't
use the alias from the above example.
The build script will automatically detect if the source tree being built
supports native-compilation, and enable it if available. You can override the
auto-detection logic to force enable or force disable native-compilation by
passing --native-comp
or --no-native-comp
respectively.
By default NATIVE_FULL_AOT
is disabled which ensures a fast build by native
compiling as few elisp source files as possible to build Emacs itself. Any
remaining elisp files will be dynamically compiled in the background the first
time they are used.
To enable native full Ahead-of-Time compilation, pass in the --native-full-aot
option, which will native-compile all of Emacs' elisp at built-time. On my
machine it takes around 10 minutes to build Emacs.app with NATIVE_FULL_AOT
disabled, and around 20-25 minutes with it enabled.
By default natively compiled *.eln
files will be cached in
~/.emacs.d/eln-cache/
. If you want to customize that, simply set a new path as
the first element of the native-comp-eln-load-path
variable. The path string
must end with a /
.
Below is an example which stores all compiled *.eln
files in cache/eln-cache
within your Emacs configuration directory:
(when (boundp 'native-comp-eln-load-path)
(setcar native-comp-eln-load-path
(expand-file-name "cache/eln-cache/" user-emacs-directory)))
By default any warnings encountered during async native compilation will pop up
a warnings buffer. As this tends to happen rather frequently with a lot of
packages, it can get annoying. You can disable showing these warnings by setting
native-comp-async-report-warnings-errors
to nil
:
(setq native-comp-async-report-warnings-errors nil)
Please see all issues with the
native-comp
label. It's a good idea if you read through them so you're familiar with the
types of issues and or behavior you can expect.
A list of known "good" commits which produce working builds is tracked in: #6 Known good commits for native-comp
- I've borrowed some ideas from David Caldwell's excellent build-emacs project, which produces all builds for emacsformacosx.com.
- Patches applied are pulled from emacs-plus, which is an excellent Homebrew formula with lots of options not available elsewhere.
- The following sources were extremely useful in figuring out how get get the
feature/native-comp
branch building on macOS:
The script downloads the source code as a gzipped tar archive from the GitHub mirror repository, as it makes it very easy to get a tarball of any given git reference.
It then runs ./configure
with a various options, including copying various
dynamic libraries into the application itself. So the built application should
in theory run on a macOS install that does not have Homebrew, or does not have
the relevant Homebrew formulas installed.
Code quality of the script itself, is well, non-existent. The build script started life a super-quick hack back in 2013, and now it's even more of a dirty hack. I might clean it up and add unit tests if I end up relying on this script for a prolonged period of time. For now I plan to use it at least until native-comp lands in a stable Emacs release for macOS.