A couple schema changes needed for GSI.

docs/sections/user_guide/yaml/components/execution.rst

@@ -34,6 +34,7 @@ Example block:
        - "--export=ALL"
        - "--ntasks $SLURM_CPUS_ON_NODE"
      mpicmd: srun
+     stacksize: 100M
      threads: 8
 
 batchargs:
@@ -83,6 +84,11 @@ mpicmd:
 
 The MPI launch program (``mpiexec``, ``srun``, et al.). This entry is only used when configuring parallel components.
 
+stacksize:
+""""""""""
+
+For drivers implementing support, exports the ``OMP_STACKSIZE`` environment variable to the execution environment, specifying the size of the stack for threads created by OpenMP. The value of this environment takes the form: *size* | *size*\ **B** | *size*\ **K** | *size*\ **M** | *size*\ **G**. When only *size* is provided, the unit is assumed to be kilobytes.
+
 threads:
 """"""""
 

src/uwtools/drivers/stager.py

@@ -20,7 +20,8 @@ def files_copied(self):
         """
         taskname, config, rundir = self.taskname, self.config, self.rundir  # type: ignore[attr-defined]
         yield taskname("files copied")
-        yield [Copier(config=config.get("files_to_copy", {}), target_dir=rundir).go()]
+        files = config.get("files_to_copy", {})
+        yield [Copier(config=files, target_dir=rundir).go() if files else None]
 
     @tasks
     def files_hardlinked(self):
@@ -29,13 +30,16 @@ def files_hardlinked(self):
         """
         taskname, config, rundir = self.taskname, self.config, self.rundir  # type: ignore[attr-defined]
         yield taskname("files hardlinked")
+        files = config.get("files_to_hardlink", {})
         yield [
             Linker(
-                config=config.get("files_to_hardlink", {}),
+                config=files,
                 target_dir=rundir,
                 hardlink=True,
                 fallback=STR.copy,
             ).go()
+            if files
+            else None
         ]
 
     @tasks
@@ -45,4 +49,5 @@ def files_linked(self):
         """
         taskname, config, rundir = self.taskname, self.config, self.rundir  # type: ignore[attr-defined]
         yield taskname("files linked")
-        yield [Linker(config=config.get("files_to_link", {}), target_dir=rundir).go()]
+        files = config.get("files_to_link", {})
+        yield [Linker(config=files, target_dir=rundir).go() if files else None]

src/uwtools/resources/jsonschema/execution-parallel.jsonschema

@@ -22,6 +22,9 @@
     "mpicmd": {
       "type": "string"
     },
+    "stacksize": {
+      "type": "string"
+    },
     "threads": {
       "minimum": 1,
       "type": "integer"

src/uwtools/resources/jsonschema/gsi.jsonschema

@@ -50,7 +50,19 @@
               "type": "string"
             },
             "update_values": {
-              "$ref": "urn:uwtools:namelist"
+              "additionalProperties": {
+                "additionalProperties": {
+                  "type": [
+                    "array",
+                    "boolean",
+                    "number",
+                    "string"
+                  ]
+                },
+                "type": "object"
+              },
+              "minProperties": 1,
+              "type": "object"
             },
             "validate": {
               "type": "boolean"

src/uwtools/tests/test_schemas.py

@@ -1160,8 +1160,8 @@ def test_schema_gsi_namelist_update_values(gsi_prop):
     )
     # At least one namelist entry is required:
     assert non_empty_dict(errors({}))
-    # At least one val/var pair is required:
-    assert non_empty_dict(errors({"nml": {}}))
+    # Allow for empty namelist entries:
+    assert not errors({"nml": {}})
 
 
 def test_schema_gsi_rundir(gsi_prop):