Hi and thanks for sharing your solution. I ran into the same issue. I tried playing with those linker flags myself but did not have the same success. After making the described modification, I'm getting the following: /usr/local/bin/perl Build --makefile_env_macros 1 Building Math-GSL Undefined symbols: "_gsl_bspline_greville_abscissa", referenced from: __wrap_gsl_bspline_greville_abscissa in BSpline_wrap.o (maybe you meant: __wrap_gsl_bspline_greville_abscissa) ld: symbol(s) not found collect2: ld returned 1 exit status error building blib/arch/auto/Math/GSL/BSpline/BSpline.bundle file from 'xs/BSpline_wrap.o' at inc/GSLBuilder.pm line 136. make: *** [all] Error 2 Tried using several different flavors of Math::GSL - CPAN, tar, development, Github. I can't get this thing to build on the Mac. Any thoughts?