@whitequark ... I would bet money that the compiler generates exactly equivalent or worse code with this "optimisation" in place compared to without it.
i eventually gave up (sdcc would generate 0x20-long records on debian and 0x10-long records on nixos and there aren't any patches in either of them and the lengths should have been compile time defines) and wrote a normalizing script because i was not prepared to spend my day doing this shit
debian actually carries one patch: it fixes a typo in the source code and two in the changelog, changes nothing else. clear sign of too much time on one's hands
really it was more complicated than that because some of the records would also be out of order and it's clear _something_ changed but i cannot for the life of me figure out what
@whitequark I recently had a failure where my code started producing different results on a different machine. I eventually tracked it down to a change in a python library I had imported to do markdown rendering. The slight formatting change caused my unchanged code to hit a latent bug and crash.
Could it be the Devian and NixOS environments are pulling in slightly different versions of dependencies?
This seems likely only if the problem comes from python, not from .c code...