Update: The story continues, but solution is not in sight yet. I upgraded a buildbot slave to Ubuntu 8.04 (Hardy) recently and now I'm getting a strange intermittent failure: sometimes cp -r /local/dir /nfs/mounted/dir fails ("process killed by signal 1", i.e. SIGHUP). I wonder if NFS is relevant or incidental to the issue? Google finds an old thread from 2005, with a workaround (usepty=False), but I'd like to understand the problem before applying random fixes.