brew installed gcc can't find brew installed gmp

Question

I used brew install gcc, and brew install gmp. However clang could compiler with option "-lgmpxx" and succeed while g++ failed I used this command:

g++ bn_p.cpp -o bn_p.out -lgmpxx -lgmp -Xpreprocessor -fopenmp

And it said:

fatal error: gmpxx.h: No such file or directory
4 | #include <gmpxx.h>

Not very much sure about brew, but I guess you should add the path to `gmpxx.h` to your include path, by flag `-I`. — Mihir Luthra, Jul 18 '19 at 03:12
Search for the path where `gmxx.h` resides and while compiling add this `-I /whateverpath/` — Mihir Luthra, Jul 18 '19 at 03:14
i have mac too but i use `macports` generally for packages. So can’t help you much with it. Hope someone else gives you the solution. — Mihir Luthra, Jul 18 '19 at 06:43
I have solved this by following your advice actually. Thank you very much. — Zijie Han, Jul 19 '19 at 07:04
@Mihir mind adding this as a response so Zijie Han can accept it? This would mark this question as answered. — bfontaine, Jul 19 '19 at 08:47
@bfontaine, what i told was just an alternative. The question specifically asks about `homebrew` and I know very little about it. My best guess is that `macports` generally asks root privileges so it may have been able to do the correct setup somehow. (sounds nonsense to me tbh) — Mihir Luthra, Jul 19 '19 at 09:24

score 0 · Answer 1 · answered Nov 23 '22 at 10:38

Installing using home-brew doesn't seem the right approach, I suggest following the instruction of another answer which seems to follow some kind of best practice

If you still prefer to use your installation using brew, I resolved my problem by running

brew info gmp

which returns the installation path, for example mine was:

/opt/homebrew/Cellar/gmp/6.2.1_1

then you just need to include the include folder as a library search path in your compilation command, for example:

g++ main.cpp -o app -I /opt/homebrew/Cellar/gmp/6.2.1_1/include

brew installed gcc can't find brew installed gmp

1 Answers1