If your GitHub Pages code includes a reference to a submodule that doesn't exist or hasn't been properly initialized, your GitHub Pages site will not build.

If your GitHub Pages site fails to build because of a missing or improperly initialized submodule, you'll receive an email that looks like this:

Subject: Page build failed

The page build failed with the following error:

"The submodule `EXAMPLE_SUBMODULE` was not properly initialized with a `.gitmodules` file.

You will only receive an email if outbound email support is enabled on your Enterprise instance. For more information, contact your site administrator.

Troubleshooting non-existent submodule errors

Tip: We strongly recommend running Jekyll locally so you can easily debug and fix build errors before pushing to your GitHub Enterprise instance. To learn more about troubleshooting options, see "Troubleshooting GitHub Pages builds."

If you haven't initialized your submodule, you will need to initialize it with the following steps:

  • In the submodule's directory, run git submodule init, then git submodule update.
  • Commit and push your changes to trigger another build on the server.