You can do, but you shouldn’t. It would either mean, that you have to copy your locally build stuff manually into the _build-tree of your actual app. Hex might complain about this and try to compile again from what it sees in its deps-tree.

Another way to use the locally compiled stuff is to use it as a :path dependency, which basically does the following:

• Copy the sources from the given path into your deps-tree
• Compile it using MIX_ENV=prod into your _build-tree
• Use it as a proper dependency

So it would roughly do the same what you had to do, but less error-prone.

Still, what you really wan’t is to use a :git-dependency. This is the easiest way to make your application available to others and make contributions free of any hurdles.

The way to check the version of a package that you pulled/cloned from git is often refered to as the version specified in the mix-file plus the actual commit-SHA you compiled from.