So I was unable to find the *logs* of the failing tests (`regressions.sum`). I'm trying locally, but I have forgotten how to run specific tests (and `make check` looks like it is going to take a while yet…).
I used to have a history entry for running the specific tests, but I seem to have lost it (or I was not doing it on the machine I thought I had). -- https://forge.sourceware.org/gcc/gcc-TEST/pulls/134#issuecomment-4886
