Finally won my fight with user mode linux from a while back.  I got a reply to my query to the mailing list saying to check for NPTL support.  Well, turns out one of the things in gentoo that I set up was a USE flag of “nptl”, which built it into libc.  Edit /etc/make.conf, re-emerge libc, and voila, it works.
Now I have to figure out new and interesting ways of using it.  I was talking to $newothercoder at work and saying that we could use it to create a staging server instead of building a new one and all the PITA factor involved in dealing with an actual physical computer.  Just a thought, but it’s nice to know why it wasn’t working for me before.
Up next, Subversion!