Spend like 3 weeks in mem-checking with valgrind and ASAN, because there seemed to be some leaks. So painful and scary. You loose all confidence in your software, the checking tool, your own sanity.
Some spurious result prevailed, could only move it around. Boss could not reproduce the problem on his machine; Ubuntu 18 with GCC 7, mine was Debian 9 with GCC 6, so I tried older Ubuntu with GCC 5. Also no problem.
Fuck it, I'm switching to clang.