Description of problem:
There is HAVE_FAST_COMPILER check in flint source. But it checks for clang or gcc 4.7.3+ in a way that gcc 5.x.y is not good enough one.
// Whether or not the compiler is good enough to compile all of t-mpz.cpp
// in reasonable time and space.
// clang 3.4 works; let's suppose all work until someone complains
#define HAVE_FAST_COMPILER 1
// gcc 4.7.3 is good enough, supposedly all higher ones are too
#define HAVE_FAST_COMPILER \
(__GNUC__ >= 4 && \
((__GNUC_MINOR__ == 7 && __GNUC_PATCHLEVEL__ >= 3) \
|| (__GNUC_MINOR__ > 7)))
#define HAVE_FAST_COMPILER 0
Some tests are not run without fast compiler, code also differ in both situations.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. do a build
Thanks for reporting the problem.
Fixed in flint-2.5.2-2.fc24