Steps to reproduce the issue

compilers.yaml

compilers:
- compiler:
    spec: gcc@11.2.0
    paths:
      cc: cc
      cxx: CC
      f77: ftn
      fc: ftn # Fortran compiler specified here
    flags: {}
    operating_system: sles15
    target: any
    modules:
    - PrgEnv-gnu
    - gcc/11.2.0
    environment: {}
    extra_rpaths: []

spack install ascent +fortran

Building conduit by itself it seems like everything is fine. conduit +fortran all builds, no problem. Or so it seems until ascent +fortran tries to configure when all of the sudden it can't find the conduit.mod file.

I went digging around and finally found the culprit, the listed projects silently hide turning off fortran when it is requested, even if there is a valid fortran compiler available. Either self.compiler.fc is not set for some reason or SPACK_FC is not set in the hostconfig stage context reliably (it is in the spack-build-env.txt file for what it is worth). Just removing all of the f_compiler logic fixes this issue, but my sense around these projects is they have some reason for doing all of these things.

This will always fail to build whatever project downstream needs conduit +fortran but never fail to build a conduit +fortran. This is really not ideal, if a spec is specified the package should build to that spec or not build at all.

hostconfig:
perlmutter-ascent-host-config.cmake.txt

Information on your system

On Perlmutter
perlmutter-ascent-build-out.txt
perlmutter-ascent-build-env.txt

* **Spack:** 0.17.1-823-28565749ff
* **Python:** 3.6.13
* **Platform:** cray-sles15-zen3
* **Concretizer:** clingo

Additional information

My environment is setup using the spack-confg for perlmutter with some minor modifications around nvidia/cuda stuff which should affect this at all. I also added the gcc@11.2.0 compiler, it is now the default in the PrgEnv-gnu.

@cyrush

General information

• I have run spack debug report and reported the version of Spack/Python/Platform
• I have run spack maintainers <name-of-the-package> and @mentioned any maintainers
• I have uploaded the build log and environment files
• I have searched the issues of this repo and believe this is not a duplicate