git-http-backend returns 500 error if repo to be cloned is a submodule

Question

I have a container that serves git repositories on a path binded to /git inside of it. This container nginx configuration: https://github.com/ipburger/alpine-http-git-server/blob/master/nginx.conf

If the repo on /git is a submodule, cloning fails with a 500 error that Nginx's fastcgi with git-http-backend doesn't output any error about it.

If the repo is not a submodule it works as usual. Why is so?

To help me debug this error, how can I find out why git-http-backend made nginx return a 500 error? There is no error message anywhere.

To help me solve this error, how can I make git-http-backend be able to clone a submodule?

Answer 1

I've solved it by passing the entire "parent" repo containing the git submodules to the container that runs git-http-backend.

Seems like git-http-backend only lets you clone submodules if the parent repo containing it is there too.