libcap is a library providing the API to access POSIX capabilities. These allow giving various kinds of specific privileges to individual users, without giving them full root permissions.
Although the Hurd design should facilitate implementing such features in a quite natural fashion, there is no support for POSIX capabilities yet. As a consequence, libcap is not available on the Hurd, and thus various packages using it can not be easily built in Debian GNU/Hurd.
The first goal of this project is implementing a dummy libcap, which doesn't actually do anything useful yet, but returns appropriate status messages, so program using the library can be built and run on Debian GNU/Hurd.
Having this, actual support for at least some of the capabilities should be implemented, as time permits. This will require some digging into Hurd internals.
Some knowledge of POSIX capabilities will need to be obtained, and for the latter part also some knowledge about the Hurd architecture. This project is probably doable without previous experience with either, though.
David Hedberg applied for this project in 2010, and though he didn't go through with it, he fleshed out many details.
Possible mentors: Samuel Thibault (youpi)
Exercise: Make libcap compile on Debian GNU/Hurd. It doesn't need to actually do anything yet -- just make it build at all for now.