Add core_compilers section

Author: alecbcs

outputs/stacks.sh

@@ -91,7 +91,7 @@ example --tee stacks/modules-1 "module --version"
 
 cat "$project/stacks/examples/8.spack.stack.yaml" > ~/stacks/spack.yaml
 spack module lmod refresh -y
-module use /home/spack/stacks/modules/linux-ubuntu22.04-x86_64
+module use /home/spack/stacks/modules/linux-ubuntu22.04-x86_64/Core
 
 example --tee stacks/modules-2 "module av"
 

outputs/stacks/examples/8.spack.stack.yaml

@@ -49,6 +49,8 @@ spack:
       roots:
         lmod: modules
       lmod:
+        core_compilers:
+          - 'gcc@12.3.0'
         hierarchy:
         - mpi
         - lapack