Checks if any calls to pthread_* or posix_* functions (except posix_openpt) expect negative return values. These functions return either 0 on success or an errno on failure, which is positive only.

Example buggy usage looks like:

if (posix_fadvise(...) < 0) {

This will never happen as the return value is always non-negative. A simple fix could be:

if (posix_fadvise(...) > 0) {