I just bumped into a problem with glibc-2.3.3.20040420, see bug #56058, and to work around the issue I reverted to glibc-2.3.2-r9, with the command: emerge "=glibc-2.3.2-r9" all went fine, the 2.3.2 glibc was compiled, installed, then the 2.3.3 removed. I even rebooted the system. but what I see now, is that the include file in question, /usr/include/semaphore.h, did not revert. I made the assumption that the include file in question belongs to the package glibc by running equery: $ equery belongs /usr/include/semaphore.h Searching for file '/usr/include/semaphore.h' in *... sys-libs/glibc-2.3.2-r9 (/usr/include/semaphore.h) Reproducible: Didn't try Steps to Reproduce: 1. emerge glibc-2.3.3.20040420 2. downgrade to glibc-2.3.2-r9 by using emerge 3. see that /usr/include/semaphore.h doesn't revert Actual Results: /usr/include/semaphore.h remained the same Expected Results: /usr/include/semaphore.h should have changed to that belonging to glibc-2.3.2-r9 the way I know what should be the /usr/include/semaphore.h file for glibc-2.3.2-r9 is that I have another system with that version of glibc, which did not ever have a higher version installed.
Created attachment 34794 [details] this is /usr/include/semaphore belonging to glibc-2.3.3.20040420
Created attachment 34795 [details] this is /usr/include/semaphore.h that belongs to glibc-2.3.2-r9
actually, it seems that the contenst of this header file is governed by the nptl USE flag...