Compiling Emacs from source is non-trivial. Here are the steps for the interested reader:

Get the source-code

git clone git://git.sv.gnu.org/emacs

This step takes a long time, because the Emacs source repository is giant. But I recommend cloning the full repo:

• It's easy to stay updated with the latest changes with git fetch in the future.
• Telling Emacs where the C source code is let's us jump all the way down into primitive functions when exploring elisp functions.

      (setq source-directory (expand-file-name "/<path>/emacs/"))
      (setq find-function-C-source-directory (expand-file-name "/<path>/emacs/src/"))
      

Make sure you have the all the dependencies installed

The easiest way to install almost all the dependencies is to run the following command:

sudo apt build-dep emacs

This command uses the information in the Ubuntu package management system. In my experience today ([2025-01-01 Wed]), this command installed everything other than libgccjit and libtree-sitter. Let's install those now:

Installing libgccjit

1. Check your gcc version with gcc --version.
2. You need to install libgccjit-<x>-dev where <x> is your gcc version.

   sudo apt install libgccjit-11-dev
   

Installing libtree-sitter

sudo apt install libtree-sitter-dev

Compile Emacs!

# Generate Configure and Make scripts:
./autogen.sh
# Run the Configure command:
./configure --without-toolkit-scroll-bars --with-x-toolkit=gtk3 --with-xpm=ifavailable --with-jpeg=ifavailable --with-gif=ifavailable --with-tiff=ifavailable --with-xml2 --with-rsvg --without-pop --with-png --with-mailutils --with-native-compilation --with-cairo --with-harfbuzz --with-tree-sitter --with-sqlite3
# If everything works:
make -j8 bootstrap
# If everything works:
make -j8
# Test the binary:
src/emacs -Q
# Install the binary:
sudo make install

Misc notes

• Running ./configure will output the default flags that Emacs plans to use.
  • If you look at the last section of what configure prints, you can check if there are new options which are not covered by my configure command above.
• To restart compilation from an absolutely clean slate, run make distclean
• To know the max number of cores you can run parallel compilation on, run nproc. This is the max value for the j parameter in the make command.

Published On: Wed, 01 Jan 2025.