PythonPackage: check purelib for libs/headers (#42602)

* PythonPackage: check purelib for libs/headers

* Update error messages too

* Fix functools.reduce argument order

1 files changed, 19 insertions, 8 deletions

diff --git a/lib/spack/spack/build_systems/python.py b/lib/spack/spack/build_systems/python.py
index f554bfef53..ec86c45633 100644
--- a/lib/spack/spack/build_systems/python.py
+++ b/lib/spack/spack/build_systems/python.py
@@ -2,7 +2,10 @@
 # Spack Project Developers. See the top-level COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+import functools
 import inspect
+import operator
 import os
 import re
 import shutil
@@ -368,16 +371,20 @@ class PythonPackage(PythonExtension):
         # Remove py- prefix in package name
         name = self.spec.name[3:]
 
-        # Headers may be in either location
+        # Headers should only be in include or platlib, but no harm in checking purelib too
         include = self.prefix.join(self.spec["python"].package.include).join(name)
         platlib = self.prefix.join(self.spec["python"].package.platlib).join(name)
-        headers = fs.find_all_headers(include) + fs.find_all_headers(platlib)
+        purelib = self.prefix.join(self.spec["python"].package.purelib).join(name)
+
+        find_all_headers = functools.partial(fs.find_all_headers, recursive=True)
+        headers_list = map(find_all_headers, [include, platlib, purelib])
+        headers = functools.reduce(operator.add, headers_list)
 
         if headers:
             return headers
 
-        msg = "Unable to locate {} headers in {} or {}"
-        raise NoHeadersError(msg.format(self.spec.name, include, platlib))
+        msg = "Unable to locate {} headers in {}, {}, or {}"
+        raise NoHeadersError(msg.format(self.spec.name, include, platlib, purelib))
 
     @property
     def libs(self) -> LibraryList:
@@ -386,15 +393,19 @@ class PythonPackage(PythonExtension):
         # Remove py- prefix in package name
         name = self.spec.name[3:]
 
-        root = self.prefix.join(self.spec["python"].package.platlib).join(name)
+        # Libraries should only be in platlib, but no harm in checking purelib too
+        platlib = self.prefix.join(self.spec["python"].package.platlib).join(name)
+        purelib = self.prefix.join(self.spec["python"].package.purelib).join(name)
 
-        libs = fs.find_all_libraries(root, recursive=True)
+        find_all_libraries = functools.partial(fs.find_all_libraries, recursive=True)
+        libs_list = map(find_all_libraries, [platlib, purelib])
+        libs = functools.reduce(operator.add, libs_list)
 
         if libs:
             return libs
 
-        msg = "Unable to recursively locate {} libraries in {}"
-        raise NoLibrariesError(msg.format(self.spec.name, root))
+        msg = "Unable to recursively locate {} libraries in {} or {}"
+        raise NoLibrariesError(msg.format(self.spec.name, platlib, purelib))
 
 
 @spack.builder.builder("python_pip")