Add py-tools variant and set $ISSM_DIR Environment Variable

packages/issm/package.py

@@ -6,6 +6,7 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
 from spack.package import *
+import os
 
 
 class Issm(AutotoolsPackage):
@@ -61,6 +62,12 @@ class Issm(AutotoolsPackage):
         description="Propagate OpenMP flags so threaded deps link cleanly",
     )
 
+    variant(
+        "py-tools",
+        default=False,
+        description="Install ISSM python files under <prefix>/python-tools",
+    )
+
     # --------------------------------------------------------------------
     # Dependencies
     # --------------------------------------------------------------------
@@ -94,10 +101,17 @@ class Issm(AutotoolsPackage):
     depends_on("access-triangle", when="+wrappers")
     depends_on("python@3.9.2:", when="+wrappers", type=("build", "run"))
     depends_on("py-numpy", when="+wrappers", type=("build", "run"))
+
+    # --------------------------------------------------------------------
+    # Conflicts
+    # --------------------------------------------------------------------
 
     # GCC 14 breaks on several C++17 constructs used in ISSM
     conflicts("%gcc@14:", msg="ISSM cannot be built with GCC versions above 13")
 
+    # +wrappers requires +py-tools to access the wrappers
+    conflicts("+wrappers", when="~py-tools", msg="The +wrappers variant requires +py-tools")
+
     # --------------------------------------------------------------------
     # Helper functions
     # --------------------------------------------------------------------
@@ -198,7 +212,39 @@ def configure_args(self):
     def install(self, spec, prefix):
         make("install", parallel=False)
 
+        # Optionally install examples directory
         if "+examples" in self.spec:
             examples_src = join_path(self.stage.source_path, "examples")
             examples_dst = join_path(prefix, "examples")
             install_tree(examples_src, examples_dst)
+
+        # Optionally install Python (.py) files
+        if "+py-tools" in spec:
+            py_src = join_path(self.stage.source_path, "src", "m")
+            py_dst = join_path(prefix, "python-tools")
+            mkdirp(py_dst)
+
+            # Recursively copy all .py files from src/m to the destination
+            for root, _, files in os.walk(py_src):
+                for file in files:
+                    if file.endswith(".py"):
+                        src_file = join_path(root, file)
+                        install(src_file, py_dst)
+
+    # --------------------------------------------------------------------
+    # Run environment - set ISSM_DIR and PYTHONPATH
+    # --------------------------------------------------------------------
+    def setup_run_environment(self, env):
+        """Set ISSM_DIR to the install root."""
+
+        # Get the prefix path (install root)
+        issm_dir = self.prefix
+
+        # Set environment variable
+        env.set('ISSM_DIR', issm_dir)
+
+        # Add ISSM python files (and shared libraries) to PYTHONPATH if +py
+        if "+py-tools" in self.spec:
+            env.prepend_path("PYTHONPATH", join_path(self.prefix, "python-tools"))
+            env.prepend_path("PYTHONPATH", join_path(self.prefix, "lib"))
+