After upgrading to the latest glibc from rawhide (glibc-2.3.1-38.i686.rpm) my old, compiled on RH 6.x with glibc 2.0, qmail installation stops working. For example, trying to run maildirsmtp fails: Incorrectly built binary which accesses errno, h_errno or _res directly. Needs to be fixed. maildirserial: fatal: unable to read /var/qmail/control/bouncefrom: no error It seems binary compatibility is broken.
Bug compatibility, not binary compatibility. The program and its libraries you're trying to run was built incorrectly, either you work around it by running it with LD_ASSUME_KERNEL=2.2.5, or you fix it and recompile.