Probably a bit of an off-case scenario, but running various nodes on Solaris 10, installed from OpenCSW. As-installed, the puppet agent fails if I include this module "but not many other modules that use gemfiles and ruby code". I've tried all manner of ensuring that /opt/csw/bin is in the $PATH but the only "fix" I've found is to ln- s /opt/csw/bin/ruby /usr/bin/ruby which clears the error.