osx hs to know explicit version of gcc

cluster_configs/local-osx.cmake

@@ -27,13 +27,13 @@ endif()
 
 if ( COMPILER STREQUAL "gnu")
     if (NO_MPI)
-        set(CMAKE_C_COMPILER       gcc      CACHE STRING "C compiler"       FORCE) # C compiler for serial build
-        set(CMAKE_CXX_COMPILER     g++      CACHE STRING "CXX compiler"     FORCE) # C++ compiler for serial build
-        set(CMAKE_Fortran_COMPILER gfortran    CACHE STRING "Fortran compiler" FORCE) # Fortran compiler for serial build
+        set(CMAKE_C_COMPILER       gcc-13      CACHE STRING "C compiler"       FORCE) # C compiler for serial build
+        set(CMAKE_CXX_COMPILER     g++-13      CACHE STRING "CXX compiler"     FORCE) # C++ compiler for serial build
+        set(CMAKE_Fortran_COMPILER gfortran-13    CACHE STRING "Fortran compiler" FORCE) # Fortran compiler for serial build
     else()
-        set(CMAKE_C_COMPILER       gcc  CACHE STRING "C compiler"       FORCE) # C compiler for parallel build
-        set(CMAKE_CXX_COMPILER     g++ CACHE STRING "CXX compiler"     FORCE) # C++ compiler for parallel build
-        set(CMAKE_Fortran_COMPILER mpifort CACHE STRING "Fortran compiler" FORCE) # Fortran compiler for parallel build
+        set(CMAKE_C_COMPILER       gcc-13  CACHE STRING "C compiler"       FORCE) # C compiler for parallel build
+        set(CMAKE_CXX_COMPILER     g++-13 CACHE STRING "CXX compiler"     FORCE) # C++ compiler for parallel build
+        set(CMAKE_Fortran_COMPILER gfortran-13 CACHE STRING "Fortran compiler" FORCE) # Fortran compiler for parallel build
     endif()
     set(comp_flags -O3 -fno-strict-aliasing -funroll-loops -march=native -std=c++0x CACHE  STRING  "comp_flags to add" FORCE)
 endif()