Can't even find an upstream compiler bug report not to mention a confirmation/patch. Doesn't look like the compiler output was analyzed at all either, they are just going by "-O3 results in valgrind warnings, -O2 doesn't".

It's not like compiler bugs are unheard of but they are rare enough that the base assumption should be that the bug is in your own code.

And not only is this blaming a compiler bug, which like sure, those do happen, it blames two compiler bugs in different programming languages. That's a red flag to me.