Exclude system CMake on Chrysalis

It is too old.

Don't exclude it on Perlmutter, where it is new enough and
can't be built with Spack.

Author: xylar

compass/machines/chrysalis.cfg

@@ -30,3 +30,6 @@ spack = /lcrc/soft/climate/compass/chrysalis/spack
 # whether to use the same modules for hdf5, netcdf-c, netcdf-fortran and
 # pnetcdf as E3SM (spack modules are used otherwise)
 use_e3sm_hdf5_netcdf = True
+
+# whether to exclude system cmake from spack build
+exclude_system_cmake = True

deploy/config.yaml.j2

@@ -159,14 +159,10 @@ spack:
   # Optional list of machine-provided Spack packages to suppress so Spack can
   # build them instead.
   #
-  # We exclude the system `cmake` so Spack can build the newer version
-  # requested in `deploy/spack.yaml.j2`.
-  #
   # The HDF5/NetCDF bundle is controlled dynamically in `pre_spack()` based on
   # merged machine config, mapping [deploy] use_e3sm_hdf5_netcdf = false to
   # excluding `hdf5_netcdf`.
-  exclude_packages:
-    - cmake
+  exclude_packages = []
 
 jigsaw:
   # If true, build/install JIGSAW + JIGSAW-Python into the pixi env

deploy/hooks.py

@@ -30,6 +30,9 @@ def pre_spack(ctx: DeployContext) -> dict[str, Any] | None:
     _maybe_exclude_e3sm_hdf5_netcdf(
         exclude_packages=exclude_packages, machine_config=ctx.machine_config
     )
+    _maybe_exclude_cmake(
+        exclude_packages=exclude_packages, machine_config=ctx.machine_config
+    )
 
     spack_path = _get_spack_path(ctx.config, ctx.machine, ctx.machine_config)
     if spack_path is not None:
@@ -141,6 +144,21 @@ def _maybe_exclude_e3sm_hdf5_netcdf(
         exclude_packages.append('hdf5_netcdf')
 
 
+def _maybe_exclude_cmake(
+    exclude_packages: list[str], machine_config
+) -> None:
+    exclude_cmake = False
+    if machine_config.has_section('deploy') and machine_config.has_option(
+        'deploy', 'exclude_system_cmake'
+    ):
+        exclude_cmake = machine_config.getboolean(
+            'deploy', 'exclude_system_cmake'
+        )
+
+    if exclude_cmake and 'cmake' not in exclude_packages:
+        exclude_packages.append('cmake')
+
+
 def _check_unsupported(
     machine: str | None, toolchain_pairs: list[tuple[str, str]]
 ) -> None: