I don't know if the ports in the "math" section should be allowed to run
make check or whatever testsuite is included however it does seem
reasonable given this message : 

+-------------------------------------------------------------+
| CAUTION:                                                    |
|                                                             |
| If you have not already run "make check", then we strongly  |
| recommend you do so.                                        |
|                                                             |
| GMP has been carefully tested by its authors, but compilers |
| are all too often released with serious bugs.  GMP tends to |
| explore interesting corners in compilers and has hit bugs   |
| on quite a few occasions.                                   |
|                                                             |
+-------------------------------------------------------------+

====> Compressing man pages (compress-man)
ison# 
ison# make check
make: don't know how to make check. Stop

make: stopped in /usr/ports/math/gmp
ison#

I have been building gmp/mpfr/mpc etc for many years on many platforms 
and I was always running the testsuite. This seems reasonable and in the
case of some interesting hardware ( RISC-V or big endian SPARC or PPC64
or whatever new thing comes along next year ) the testsuite is prudent.

Just an idea. 

-- 
Dennis Clarke
RISC-V/SPARC/PPC/ARM/CISC
UNIX and Linux spoken
GreyBeard and suspenders optional