I can start with a brand new 9.0 install, urpmi glibc from cooker and thenHmm, you answered to half of the questions. My test machine was a 9.0 as well. Then, I hand-installed glibc-2.3.1-1mdk at some point then urpmi --auto-select everything from cooker. It still works.
everything segs from that point on.
Do you really get segfaults? Try LD_DEBUG=libs <something that crashes for you>.
