I have a project that I am developing built off CodeIgniter. The main part of the project is a private system I am creating, but I want to add it to source control, to gain all the associated goodies. Now I'm using Mercurial, so I did the whole hg init bit, so I've got the repository set up.

Now, one of the things I've done is to make a library for CodeIgniter, which I use in this project. Now I want to make this library open, so I need a separate repo for that.

For anyone unfamiliar with CodeIgniter library development, here's a reference:

application /config <- configuration files /libraries <- library logic in here

Now I will probably develop a few more libraries in the course of this project, so I can't just dump a repo in the application folder without clumping them all together.

What I did was this:

dev/ci/library <- library here dev/project <- project here

Now in both of those folders, I have made a repository. What I want to do is make the project repository automatically reference the library repository, so I can have a private and a public repository, as I explained earlier.

The main way to do this, I have read, is to use subrepositories, but I can only find examples on nested ones (which are unclear anyway, I find). How do I make it reference another repository like svn:externals?