Why shouldn't I include <bits/sigaction.h>, and how do I ignore the error when I do so?

Question

I'm currently trying to instrument part of the SPEC OMP 2012 benchmark suite using the Score-P profiling tool, and I'm getting an error. Specifically:

/XXX/imagick/src/magick_magick.c: In function ‘SetMagickSignalHandler’:
/XXX/imagick/src/magick_magick.c:1137:20: error: storage size of ‘action’ isn’t known
    struct sigaction action, previous_action;

Based on information I found here, the problem is that when I compile with -std=c99 (using gcc 6.2.1), the compiler doesn't recognize sigaction as it's not in the C99 spec.

Interestingly, when I compile without Score-P, I don't have this problem at all. But that's another story.

All of that being said, I still need to instrument this program. I don't care about portability either. And I'm aware of the fact that you should not directly include <bits/sigaction.h>. With that in mind, I'd still like to know:

1. How do I ignore the #error that gets thrown as soon as I try to compile>

2. Why does this error exist?