annoying edge cases: there's probably some vital software out there that only compiles on GCC 2.96

for those who don't feel the full terror:
GCC 2.96 never existed. When 2.95.3 was the latest, Redhat got annoyed that GCC 3.0 was not finished at the time, so they pulled the unfinished code for it from the CVS and heavily patched it into sorta-working, and called it GCC 2.96

2.96 was not approved by the GCC team, and it had a bunch of problems like NOT BEING ABLE TO COMPILE LINUX, because it was essentially an in-progress dev branch that Redhat just decided to promote to a full release because they had a deadline

because of ABI incompatibilities, code made with 2.96 isn't compatible with either GCC 2.95 or GCC 3.0, so it's a weird cul-de-sac of redhat-invented incompatibility.

there's still an official statement from the GCC Steering Committee about "GCC 2.96" on the GCC site:
https://gcc.gnu.org/gcc-2.96.html 

and presumably there was some less-public communications between GCC & Redhat along the lines of DON'T FUCKING DO THAT

I should have waited a little, it turns out that statement came out almost exactly 20 years ago.

it'd be 20 years on monday.

and it turns out at least one person did run into this problem.
they've got GCC 2.96 only code.