Problem with `modules.yaml` not found after spack config related changes

[albestro]

Reporting here what @boeschf already reported on slack earlier this month.

spack/spack#51162 seems to have broke stackinator.

Stackinator
  recipe path: .
  build path : /dev/shm/boeschf
  system     : /capstor/scratch/cscs/boeschf/pytorch-uenv/alps-cluster-config/daint
  mount      : default
  build cache: /capstor/scratch/cscs/boeschf/.uenv-images/uenv-cache-private-config.yaml
  develop    : False
spack: clone repository https://github.com/spack/spack.git to /dev/shm/boeschf/spack
spack: fetching dc7e4a2de12347597f2ae0eb8570704cf4ccd51f
spack: checking out dc7e4a2de12347597f2ae0eb8570704cf4ccd51f
spack: commit hash is dc7e4a2de12347597f2ae0eb8570704cf4ccd51f
spack-packages: clone repository https://github.com/spack/spack-packages.git to /dev/shm/boeschf/spack-packages
spack-packages: fetching e7bc1e5ce28e7af95a893ac3a32529e6fc75c738
spack-packages: checking out e7bc1e5ce28e7af95a893ac3a32529e6fc75c738
spack-packages: commit hash is e7bc1e5ce28e7af95a893ac3a32529e6fc75c738
Traceback (most recent call last):
  File "/capstor/scratch/cscs/boeschf/pytorch-uenv/stackinator/stackinator/main.py", line 88, in main
    builder.generate(recipe)
    ~~~~~~~~~~~~~~~~^^^^^^^^
  File "/capstor/scratch/cscs/boeschf/pytorch-uenv/stackinator/stackinator/builder.py", line 474, in generate
    modules_yaml = recipe.modules_yaml
                   ^^^^^^^^^^^^^^^^^^^
  File "/capstor/scratch/cscs/boeschf/pytorch-uenv/stackinator/stackinator/recipe.py", line 317, in modules_yaml
    with self.modules.open() as fid:
         ~~~~~~~~~~~~~~~~~^^
  File "/users/boeschf/.local/aarch64/share/uv/python/cpython-3.13.5-linux-aarch64-gnu/lib/python3.13/pathlib/_local.py", line 537, in open
    return io.open(self, mode, buffering, encoding, errors, newline)
           ~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
FileNotFoundError: [Errno 2] No such file or directory: '/dev/shm/boeschf/spack/etc/spack/defaults/modules.yaml'

[Errno 2] No such file or directory: '/dev/shm/boeschf/spack/etc/spack/defaults/modules.yaml'
see /tmp/boeschf/log_stackinator_20251104-084817 for more information

We fall back to a copy of the modules path from Spack.

Solution foreseen by @bcumming is to remove the module build step, which requires hacking on the makefile structure.

[msimberg]

Do you know if that still reproduces with spack 1.1? I was able to build eth-cscs/alps-uenv#262 with releases/v1.1, but there might be recipe-specific differences that make it work in one case and not in another.

[albestro]

AFAIU the problem applies when

• config:modules:true but no modules.yaml is provided in the recipe
• config:modules:false

eth-cscs/alps-uenv#262 has modules.yaml in the recipe.

IMHO the first case makes sense because it fallbacks to the default one provided by spack, but the second one is a bit surprising (why should we use a default module configuration when we don't want modules?!).