Install submodules when deploying through the Heroku API (eg, with GitHub Sync).

Heroku will automatically fetch submodules when deploying your app with a GIT push.
However, deploying it through the API (which is used by GitHub Sync) will not do so as it doesn't get your git repository data.

This buildpack will parse your .gitmodules file for all submodules and install all of them during your build.

heroku buildpacks:add https://github.com/dmathieu/heroku-buildpack-submodules

In your .gitmodules file you can specify a branch name or an exact exact revision to check out.

For example to specify a branch:

[submodule "path/to/checkout"]	path = "path/to/checkout"	url = https://github.com/someuser/somerepo.git	branch = mybranch 

To specify an exact revision:

[submodule "path/to/checkout"]	path = "path/to/checkout"	url = https://github.com/someuser/somerepo.git	revision = d97f4bf 

Enjoy!