composer/composer — pull request #354 by perprogramming (2012-02-23 11:25:36+00:00)
Title: Make mercurial dev-branches updateable

Although the tag "tip" does not provide a valid package version (see VersionParser), the implementation of HgDriver::getSource uses tip as the preferred label for the branch that tip is currently on.

This is not a problem at first hand because you can install a new package correctly with "tip" as source reference.

The problem is that any new revision on that branch won't lead to a new package, because the package will always refer to the same reference "tip".

Therefore you cannot update your project to the new version with "composer update".