报错1：
In file included from src/gmpy2.c:426:
src/gmpy.h:106:12: fatal error: 'gmp.h' file not found
# include "gmp.h"
^~~~~~~
1 error generated.
error: command 'gcc' failed with exit status 1
解决方法：
brew install gmp
报错2：
In file included from src/gmpy2.c:426:
src/gmpy.h:252:12: fatal error: 'mpfr.h' file not found
# include "mpfr.h"
^~~~~~~~
1 error generated.
error: command 'gcc' failed with exit status 1
解决方法：
brew install libmpc