...
2. Check available compilers:
$ spack compiler list
==> Available compilers
-- gcc rocky9-x86_64 --------------------------------------------
[e] gcc@13.2.0
3. Concretize a sample spec (reusing externals):
$ spack spec -Ilt quantum-espresso~mpi
==> Warning: Spack is trying attach a Python dependency to 'meson@=1.1.1 build_system=python_pip platform=linux os=rocky9 target=aarch64'. This feature is deprecated, and will be removed in v1.2. Please make the dependency explicit in your configuration.
==> Error: failed to concretize `quantum-espresso~mpi` for the following reasons:
1. Only external, or concrete, compilers are allowed for the fortran language
2. Only external, or concrete, compilers are allowed for the cxx language
3. Only external, or concrete, compilers are allowed for the c language
@lorisercole Any idea from the top of your head what may cause this?