These are the ruby wrappers for libgearman which can be used to connect to Gearman.
The C source here is generated from SWIG. That, as well as the larger build process of which it is a part and from which this source package is derived can be checked out from launchpad via:
bzr branch lp:gearman-interface
If you just want to build/install this without doing developement on the C code, then this source dir is all you need. If you want to develop on the C bindings themselves, then you’ll need the full gearman-interface source tree.
You will need to install echoe from gem:
gem install echoe
From that point, rake compile should do the trick.