Error installing similarity:
ERROR: Failed to build gem native extension.
/usr/local/Cellar/gsl/1.15/include/gsl/gsl_matrix_complex_double.h:227: error: previous declaration of ‘gsl_matrix_complex_equal’ was here
make: *** [matrix_complex.o] Error 1
i think the error is related to the v1.15 of gsl
this post show how to make it work with version 1.14 of gsl