I just wanted to say that I had the exact problem on OSX. Rather than setting an environment variable, I used an additional compiler flag -L/opt/local/lib, which then lets one use -lgsl. I reference this answer.
I just wanted to say that I had the exact problem on OSX. Rather than setting an environment variable, I used an additional compiler flag -L/opt/local/lib, which then lets one use -lgsl. I reference this answer.