Emacs: building from source on macOS

I've always wanted to build Emacs from source as it lets you try new features. Native compilation in particular was something I wanted to explore. Native compilation leverages libgccjit to compile Emacs lisp code to native code making Emacs very snappy.

Why not use Homebrew? Homebrew is great and I still use it for installing dependencies like libgccjit but recently Homebrew has started removing options on their code formulae which makes it a lot less convenient for messing around with emacs.

Let's get started.

Install dependencies.

brew install libxml2 gcc libgccjit

Clone Emacs 28 from savannah. We clone a single branch for a slightly smaller download size.

git clone https://git.savannah.gnu.org/git/emacs.git --branch emacs-28 --single-branch

Configure build:

cd emacs
git checkout emacs-28
./configure --with-cairo --with-imagemagick --with-xwidgets --with-native-compilation

Start the build. Worth pointing out building emacs from source does take some time -j$(nproc) ensures you are at least using all your system's cores.

make -j$(nproc)
make clean install

Move the executable to Applications folder.

mv nextSteps/Emacs.app /Applications

The only problem I ran into was Emacs not being able to find libgccjit this was solved by making sure exec-path-from-shell was the first package that loaded by use package in my init.el.

With this knowledge you can now build a specific version of Emacs with options you want to try. Liberating.