Is there a way to create external link in Mercurial

Question

I'm trying to include an older version of some lib into a new project. Is there a way to notify the current repository that I only need specific revision of other library, and not the tip?

Answer 1

In newer versions of Mercurial there is the concept of sub-repositories or subrepos, and there is an .hgsubstate file in the base directory of a project that records which version of each subrepo is the one that's being used. That should solve your problem if the other library is maintained in a Mercurial repository.