First, apologies if this question has been answered elsewhere or I am doing something really stupid. I have searched for several hours for a solution to my problem with no success. I am trying to do a GCC build of a mix of C and Fortran source that has been successfully compiled for many years with both the PGI and Intel compilers. I have one Fortran routine that calls "qsort", a sorting routine provided in most libraries. I know it is provided in the GCC libraries. However, because the call is from Fortran code, it will properly link with the library and I get this error: Undefined symbols for architecture x86_64: "_qsort_", referenced from: I understand that the trailing underscore is the problem, but I cannot use the "no-underscoring" compiler flags because the code also links to other libraries that do provide the underscore which then breaks everything else. I am using gfortran to do the linking though I get the same error with gcc. I am using version 4.8 currently but get the same error with 4.7. Everything is on OS X, 10.7. Any help would be greatly appreciated. Thank you. _____ David
