soyWXY

In qtest.c, using non-reentrant function in signal handler can lead to unpredictable result.

2

In sigsegvhandler(), report() is called, which invocates non-reentrant stdio functions. I check [signal-safety(7) — Linux manual page](https://man7.org/linux/man-pages/man7/signal-safety.7.html) to determine whether a function is reentrant, and I wonder if this should...