# build-emacs-for-macos 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. ## Why? - 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. ## Binary Builds Nightly and stable binary builds produced with this build script are available from [jimeh/emacs-builds](https://github.com/jimeh/emacs-builds). ## Limitations 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. ## Requirements Required with both Nix and Homebrew approaches: - [Xcode](https://apps.apple.com/gb/app/xcode/id497799835?mt=12) ### Nix The [Nix](https://nixos.org/) 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 ``` ### Homebrew If you do not have Nix installed, then the alternative way to manage and install build-time dependencies is via [Homebrew](https://brew.sh/). 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 ``` ## Status As of writing (2024-11-30) it works for me on my machine and for the nightly builds in [jimeh/emacs-builds](https://github.com/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](https://github.com/jimeh/emacs-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. ## Usage ### Nix Ensure [Flakes](https://nixos.wiki/wiki/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` ### Homebrew Run `make boostrap` to ensure all Ruby and Homebrew dependencies are installed. ### Build Script ``` Usage: ./build-emacs-for-macos [options] 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-]xwidgets Enable/disable XWidgets if supported (default: enabled) --[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-titlebar Apply no-titlebar patch (default: disabled) --posix-spawn Apply posix-spawn patch (deprecated) --no-frame-refocus Apply no-frame-refocus patch (default: disabled) --[no-]poll Apply poll patch (deprecated) --[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: /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. ### Examples 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](https://github.com/emacs-mirror/emacs) GitHub repository. Hence to get a list of tags/branches available to install, simply check said repository. ## Use Emacs.app as `emacs` CLI Tool 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`: ```bash 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. ## Native-Comp 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. ### Configuration #### Native-Lisp Cache Directory 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: ```elisp (when (boundp 'native-comp-eln-load-path) (setcar native-comp-eln-load-path (expand-file-name "cache/eln-cache/" user-emacs-directory))) ``` #### Compilation Warnings 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`: ```elisp (setq native-comp-async-report-warnings-errors nil) ``` ### Issues Please see all issues with the [`native-comp`](https://github.com/jimeh/build-emacs-for-macos/issues?q=is%3Aissue+is%3Aopen+label%3Anative-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. ### Known Good Commits/Builds A list of known "good" commits which produce working builds is tracked in: [#6 Known good commits for native-comp](https://github.com/jimeh/build-emacs-for-macos/issues/6) ## Credits - I've borrowed some ideas from [David Caldwell](https://github.com/caldwell)'s excellent [build-emacs](https://github.com/caldwell/build-emacs) project, which produces all builds for [emacsformacosx.com](https://emacsformacosx.com). - Patches applied are pulled from [emacs-plus](https://github.com/d12frosted/homebrew-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: - https://gist.github.com/mikroskeem/0a5c909c1880408adf732ceba6d3f9ab#1-gcc-with-libgccjit-enabled - https://github.com/shshkn/emacs.d/blob/master/docs/nativecomp.md - https://gist.github.com/AllenDang/f019593e65572a8e0aefc96058a2d23e ## Internals The script downloads the source code as a gzipped tar archive from the [GitHub mirror](https://github.com/emacs-mirror/emacs) 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. ## License [CC0 1.0 Universal](http://creativecommons.org/publicdomain/zero/1.0/)