Separable module configurations (#22588)

Currently, module configurations are inconsistent because modulefiles are generated with the configs for the active environment, but are shared among all environments (and spack outside any environment).

This PR fixes that by allowing Spack environments (or other spack config scopes) to define additional sets of modules to generate. Each set of modules can enable either lmod or tcl modules, and contains all of the previously available module configuration. The user defines the name of each module set -- the set configured in Spack by default is named "default", and is the one returned by module manipulation commands in the absence of user intervention.

As part of this change, the module roots configuration moved from the `config` section to inside each module configuration.

Additionally, it adds a feature that the modulefiles for an environment can be configured to be relative to an environment view rather than the underlying prefix. This will not be enabled by default, as it should only be enabled within an environment and for non-default views constructed with separate projections per-spec.

TODO:
- [x] code changes to support multiple module sets
- [x] code changes to support modules relative to a view
- [x] Tests for multiple module configurations
- [x] Tests for modules relative to a view
- [x] Backwards compatibility for module roots from config section
- [x] Backwards compatibility for default module set without the name specified
- [x] Tests for backwards compatibility

4 files changed, 27 insertions, 22 deletions

diff --git a/etc/spack/defaults/config.yaml b/etc/spack/defaults/config.yaml
index 61c23f42df..2400686e60 100644
--- a/etc/spack/defaults/config.yaml
+++ b/etc/spack/defaults/config.yaml
@@ -33,13 +33,6 @@ config:
   template_dirs:
     - $spack/share/spack/templates
 
-
-  # Locations where different types of modules should be installed.
-  module_roots:
-    tcl:    $spack/share/spack/modules
-    lmod:   $spack/share/spack/lmod
-
-
   # Temporary locations Spack can try to use for builds.
   #
   # Recommended options are given below.
diff --git a/etc/spack/defaults/darwin/modules.yaml b/etc/spack/defaults/darwin/modules.yaml
index a90cc24c60..3bfca8c613 100644
--- a/etc/spack/defaults/darwin/modules.yaml
+++ b/etc/spack/defaults/darwin/modules.yaml
@@ -14,8 +14,9 @@
 #   ~/.spack/modules.yaml
 # -------------------------------------------------------------------------
 modules:
-  prefix_inspections:
-    lib:
-      - DYLD_FALLBACK_LIBRARY_PATH
-    lib64:
-      - DYLD_FALLBACK_LIBRARY_PATH
+  default:
+    prefix_inspections:
+      lib:
+        - DYLD_FALLBACK_LIBRARY_PATH
+      lib64:
+        - DYLD_FALLBACK_LIBRARY_PATH
diff --git a/etc/spack/defaults/linux/modules.yaml b/etc/spack/defaults/linux/modules.yaml
index a86a4794f1..353a6ea9ab 100644
--- a/etc/spack/defaults/linux/modules.yaml
+++ b/etc/spack/defaults/linux/modules.yaml
@@ -14,8 +14,9 @@
 #   ~/.spack/modules.yaml
 # -------------------------------------------------------------------------
 modules:
-  prefix_inspections:
-    lib:
-      - LD_LIBRARY_PATH
-    lib64:
-      - LD_LIBRARY_PATH
+  default:
+    prefix_inspections:
+      lib:
+        - LD_LIBRARY_PATH
+      lib64:
+        - LD_LIBRARY_PATH
diff --git a/etc/spack/defaults/modules.yaml b/etc/spack/defaults/modules.yaml
index d6d245930c..4539dbc9c2 100644
--- a/etc/spack/defaults/modules.yaml
+++ b/etc/spack/defaults/modules.yaml
@@ -14,8 +14,7 @@
 #   ~/.spack/modules.yaml
 # -------------------------------------------------------------------------
 modules:
-  enable:
-    - tcl
+  # Paths to check when creating modules for all module sets
   prefix_inspections:
     bin:
       - PATH
@@ -34,6 +33,17 @@ modules:
     '':
       - CMAKE_PREFIX_PATH
 
-  lmod:
-    hierarchy:
-      - mpi
+  # These are configurations for the module set named "default"
+  default:
+    # Where to install modules
+    roots:
+      tcl:    $spack/share/spack/modules
+      lmod:   $spack/share/spack/lmod
+    # What type of modules to use
+    enable:
+      - tcl
+
+    # Default configurations if lmod is enabled
+    lmod:
+      hierarchy:
+        - mpi