Digging around in the various pages and manuals on gcc.gnu.org has not shed light on what release supports what OS/arch. The real question is what was the last release to support AIX ver x.y on IBM RS/6000 or perhaps some variation of HP/UX on an old SuperDome? I can not find anything anywhere that says "this should work" as well as "this will not work" or even "good luck". Looking at Host/Target specific installation notes for GCC : https://gcc.gnu.org/install/specific.html#older There I see : Starting with GCC 3.1, each release has a list of “obsoleted” systems. Support for these systems is still present in that release, but configure will fail unless the --enable-obsolete option is given. Unless a maintainer steps forward, support for these systems will be removed from the next release of GCC. Really? Where is that list? If anyone knows where inside the source tree one would find such a list of "supported" and/or "obsoleted” systems that would be so very helpful to those of us that drag around museum pieces.[1] -- -- Dennis Clarke RISC-V/SPARC/PPC/ARM/CISC UNIX and Linux spoken [1] I may be a museum piece also but not worth the price of admission