Python: improve site_packages_dir handling (#28346)

* Python: improve site_packages_dir handling

* Replace all site_packages_dir with purelib/platlib

3 files changed, 27 insertions, 33 deletions

diff --git a/lib/spack/spack/bootstrap.py b/lib/spack/spack/bootstrap.py
index 16195ff381..bdf69303c6 100644
--- a/lib/spack/spack/bootstrap.py
+++ b/lib/spack/spack/bootstrap.py
@@ -78,13 +78,10 @@ def _try_import_from_store(module, query_spec, query_info=None):
 
     for candidate_spec in installed_specs:
         pkg = candidate_spec['python'].package
-        purelib = pkg.config_vars['python_lib']['false']['false']
-        platlib = pkg.config_vars['python_lib']['true']['false']
-
-        module_paths = [
-            os.path.join(candidate_spec.prefix, purelib),
-            os.path.join(candidate_spec.prefix, platlib),
-        ]
+        module_paths = {
+            os.path.join(candidate_spec.prefix, pkg.purelib),
+            os.path.join(candidate_spec.prefix, pkg.platlib),
+        }
         sys.path.extend(module_paths)
 
         try:
diff --git a/lib/spack/spack/build_systems/python.py b/lib/spack/spack/build_systems/python.py
index 2d003f38e3..59fd057c6a 100644
--- a/lib/spack/spack/build_systems/python.py
+++ b/lib/spack/spack/build_systems/python.py
@@ -128,22 +128,24 @@ class PythonPackage(PackageBase):
             list: list of strings of module names
         """
         modules = []
-        root = os.path.join(
-            self.prefix,
-            self.spec['python'].package.config_vars['python_lib']['true']['false'],
-        )
+        pkg = self.spec['python'].package
+
+        # Packages may be installed in platform-specific or platform-independent
+        # site-packages directories
+        for directory in {pkg.platlib, pkg.purelib}:
+            root = os.path.join(self.prefix, directory)
 
-        # Some Python libraries are packages: collections of modules
-        # distributed in directories containing __init__.py files
-        for path in find(root, '__init__.py', recursive=True):
-            modules.append(path.replace(root + os.sep, '', 1).replace(
-                os.sep + '__init__.py', '').replace('/', '.'))
+            # Some Python libraries are packages: collections of modules
+            # distributed in directories containing __init__.py files
+            for path in find(root, '__init__.py', recursive=True):
+                modules.append(path.replace(root + os.sep, '', 1).replace(
+                    os.sep + '__init__.py', '').replace('/', '.'))
 
-        # Some Python libraries are modules: individual *.py files
-        # found in the site-packages directory
-        for path in find(root, '*.py', recursive=False):
-            modules.append(path.replace(root + os.sep, '', 1).replace(
-                '.py', '').replace('/', '.'))
+            # Some Python libraries are modules: individual *.py files
+            # found in the site-packages directory
+            for path in find(root, '*.py', recursive=False):
+                modules.append(path.replace(root + os.sep, '', 1).replace(
+                    '.py', '').replace('/', '.'))
 
         modules = [mod for mod in modules if re.match('[a-zA-Z0-9._]+$', mod)]
 
@@ -258,18 +260,13 @@ class PythonPackage(PackageBase):
         # Get all relative paths since we set the root to `prefix`
         # We query the python with which these will be used for the lib and inc
         # directories. This ensures we use `lib`/`lib64` as expected by python.
-        pure_site_packages_dir = spec['python'].package.config_vars[
-            'python_lib']['false']['false']
-        plat_site_packages_dir = spec['python'].package.config_vars[
-            'python_lib']['true']['false']
-        inc_dir = spec['python'].package.config_vars['python_inc']['true']
-
+        pkg = spec['python'].package
         args += ['--root=%s' % prefix,
-                 '--install-purelib=%s' % pure_site_packages_dir,
-                 '--install-platlib=%s' % plat_site_packages_dir,
+                 '--install-purelib=%s' % pkg.purelib,
+                 '--install-platlib=%s' % pkg.platlib,
                  '--install-scripts=bin',
                  '--install-data=',
-                 '--install-headers=%s' % inc_dir
+                 '--install-headers=%s' % pkg.include,
                  ]
 
         return args
diff --git a/lib/spack/spack/build_systems/sip.py b/lib/spack/spack/build_systems/sip.py
index 49fdd621ee..def333d8e6 100644
--- a/lib/spack/spack/build_systems/sip.py
+++ b/lib/spack/spack/build_systems/sip.py
@@ -67,7 +67,7 @@ class SIPPackage(PackageBase):
         modules = []
         root = os.path.join(
             self.prefix,
-            self.spec['python'].package.config_vars['python_lib']['true']['false'],
+            self.spec['python'].package.platlib,
         )
 
         # Some Python libraries are packages: collections of modules
@@ -114,7 +114,7 @@ class SIPPackage(PackageBase):
             '--sip-incdir', join_path(spec['py-sip'].prefix.include,
                                       python_include_dir),
             '--bindir', prefix.bin,
-            '--destdir', inspect.getmodule(self).site_packages_dir,
+            '--destdir', inspect.getmodule(self).python_platlib,
         ])
 
         self.python(configure, *args)
@@ -167,7 +167,7 @@ class SIPPackage(PackageBase):
         module = self.spec['py-sip'].variants['module'].value
         if module != 'sip':
             module = module.split('.')[0]
-            with working_dir(inspect.getmodule(self).site_packages_dir):
+            with working_dir(inspect.getmodule(self).python_platlib):
                 with open(os.path.join(module, '__init__.py'), 'a') as f:
                     f.write('from pkgutil import extend_path\n')
                     f.write('__path__ = extend_path(__path__, __name__)\n')