Description of problem: We are testing our app with RHEL5.1 x86_64, but some parts of the app are still compiled on RHEL3 i386. These worked fine on RHEL4 i386 with the compat libs. I see that RHEL5.1 does not have compat libs for RHEL3. I just wanted to check on the official backwards compatibility policy of Red Hat. It looks like it is one release back is supported, but not two. Is that correct? Thanks! How reproducible: .n.a Version-Release number of selected component (if applicable): 5.1 How reproducible: Steps to Reproduce: 1. 2. 3. Actual results: Additional Info: We guarantee core libraries for n+2 compat-glibc-2.3.2-95.30 is not in RHEL5. Since we do support stuff to N+2 then is should be in there. I tried building it but I got compat-gcc-32 >= 3.2.3 is needed by compat-glibc-2.3.2-95.30.i386 compat-gcc-32 >= 3.2.1-5 is needed by compat-glibc-2.3.2-95.30.i38 compat-gcc-32 is also not available for RHEL5 but compat-gcc-32-3.2.3-61.src.rpm is available on the RHEL5.2 SRPM DVD.
We guarantee runtime compatibility for n-2, but definitely not (and never did) guarantee devel compatibility for n-2, only (selected parts of) n-1. compat-glibc is devel only package (headers and linker stub for linking), so it is ok that RHEL3 glibc isn't covered in RHEL5. RHEL5 glibc (which is the runtime package) supports RHEL2.1/RHEL3/RHEL4/RHEL5 linked programs and shared libraries (as long as they don't invoke undefined behavior of course). In RHEL5 from compat-gcc-32 src.rpm we just build the needed runtime library package (compat-libstdc++-33).