If anyone is interested, the problem was finally solved the other day. It went all the way up to the top level support at IBM, so I feel better that it wasn't something stupid.
The problem is that the nscd (name service cache daemon) wasn't running on the boxes that Clearcase was failing on. We work in an LDAP environment, but the Clearcase clients don't. Nscd is configured to bypass the LDAP authentication via /etc/nscd.conf, and since nscd wasn't running, authentication fell back to LDAP configured in /etc/nsswitch.conf used by the dns(?).
The clue came by analyzing output from tcpdump and strace which showed Clearcase trying to connect to an LDAP server, which was being rejected causing the signal 13 error. Once nscd was running, we did another tcpdump/strace round and the output revealed everything was happy.
Hopefully, this can be useful to some other unfortunate soul down the road.
- Doug
-- Nothing is impossible if ImPossible