svn got confused trying to incorporate updates to the email pkg. Slaves
sparc solaris10 gcc trunk and x86 gentoo trunk
got stuck in their trunk "updating" steps for 7 hours, presumably as a result.
I killed those builds, and tried to start new builds on those slaves. There was no effect apart from their "pending" count rising from 6 to 7. They respond to pings, but won't start another build.
I'm not sure how they get into such a state (but saw it at Zope Corp at times too). It's possible that their buildbot processes need to be restarted, and/or that the master process needs to be restarted.