At my previous job a colleague showed me some C++ code and asked if I could help him spot the issue. I looked at it and said it looked fine. He ran the program

At my previous job a colleague showed me some C++ code and asked if I could help him spot the issue. I looked at it and said it looked fine. He ran the program and it crashed. We ended up staying late in order to try to find a minimal reproducible example. We finally managed and found that the cause was a basic trigonometric function in the standard library giving the wrong result. At first, we couldn't believe it. Then we googled the issue and found a bug report about the intrinsic version of that function not working properly. With Microsoft confirming that it didn't and that they weren't looking to fix it. We disabled intrinsics in that section of the code and the original code worked as intended.