py-torch: re-add headers/libs properties (#31446)

var/spack/repos/builtin/packages/py-torch/package.py

@@ -269,6 +269,37 @@ class PyTorch(PythonPackage, CudaPackage):
     patch('https://github.com/pytorch/pytorch/commit/c74c0c571880df886474be297c556562e95c00e0.patch?full_index=1',
           sha256='8ff7d285e52e4718bad1ca01ceb3bb6471d7828329036bb94222717fcaa237da', when='@:1.9.1 ^cuda@11.4.100:')
 
+    @property
+    def headers(self):
+        """Discover header files in platlib."""
+
+        # Headers may be in either location
+        include = join_path(self.prefix, self.spec['python'].package.include)
+        platlib = join_path(self.prefix, self.spec['python'].package.platlib)
+        headers = find_all_headers(include) + find_all_headers(platlib)
+
+        if headers:
+            return headers
+
+        msg = 'Unable to locate {} headers in {} or {}'
+        raise NoHeadersError(msg.format(self.spec.name, include, platlib))
+
+    @property
+    def libs(self):
+        """Discover libraries in platlib."""
+
+        # Remove py- prefix in package name
+        library = 'lib' + self.spec.name[3:].replace('-', '?')
+        root = join_path(self.prefix, self.spec['python'].package.platlib)
+
+        for shared in [True, False]:
+            libs = find_libraries(library, root, shared=shared, recursive=True)
+            if libs:
+                return libs
+
+        msg = 'Unable to recursively locate {} libraries in {}'
+        raise NoLibrariesError(msg.format(self.spec.name, root))
+
     @when('@1.5.0:')
     def patch(self):
         # https://github.com/pytorch/pytorch/issues/52208

var/spack/repos/builtin/packages/python/package.py

@@ -1297,6 +1297,7 @@ def setup_dependent_package(self, module, dependent_spec):
 
         module.python = self.command
 
+        module.python_include = join_path(dependent_spec.prefix, self.include)
         module.python_platlib = join_path(dependent_spec.prefix, self.platlib)
         module.python_purelib = join_path(dependent_spec.prefix, self.purelib)