add test to verify that $PYTHONPATH or $EBPYTHONPREFIXES are set correctly by generated module file

easybuild/framework/easyblock.py

@@ -1390,6 +1390,37 @@ def make_module_description(self):
         """
         return self.module_generator.get_description()
 
+    def make_module_pythonpath(self):
+        """
+        Add lines for module file to update $PYTHONPATH or $EBPYTHONPREFIXES,
+        if they aren't already present and the standard lib/python*/site-packages subdirectory exists
+        """
+        lines = []
+        if not os.path.isfile(os.path.join(self.installdir, 'bin', 'python')):  # only needed when not a python install
+            python_subdir_pattern = os.path.join(self.installdir, 'lib', 'python*', 'site-packages')
+            candidate_paths = (os.path.relpath(path, self.installdir) for path in glob.glob(python_subdir_pattern))
+            python_paths = [path for path in candidate_paths if re.match(r'lib/python\d+\.\d+/site-packages', path)]
+
+            runtime_deps = [dep['name'] for dep in self.cfg.dependencies(runtime_only=True)]
+            use_ebpythonprefixes = all([
+                'Python' in runtime_deps,
+                build_option('prefer_python_search_path') == EBPYTHONPREFIXES,
+                not self.cfg['force_pythonpath']
+            ])
+
+            if python_paths:
+                # add paths unless they were already added
+                if use_ebpythonprefixes:
+                    path = ''  # EBPYTHONPREFIXES are relative to the install dir
+                    if path not in self.module_generator.added_paths_per_key[EBPYTHONPREFIXES]:
+                        lines.append(self.module_generator.prepend_paths(EBPYTHONPREFIXES, path))
+                else:
+                    for python_path in python_paths:
+                        if python_path not in self.module_generator.added_paths_per_key[PYTHONPATH]:
+                            lines.append(self.module_generator.prepend_paths(PYTHONPATH, python_path))
+
+        return lines
+
     def make_module_extra(self, altroot=None, altversion=None):
         """
         Set extra stuff in module file, e.g. $EBROOT*, $EBVERSION*, etc.
@@ -1438,26 +1469,8 @@ def make_module_extra(self, altroot=None, altversion=None):
                                      value, type(value))
             lines.append(self.module_generator.append_paths(key, value, allow_abs=self.cfg['allow_append_abs_path']))
 
-        # Add automatic PYTHONPATH or EBPYTHONPREFIXES if they aren't already present and python paths exist
-        if not os.path.isfile(os.path.join(self.installdir, 'bin/python')):  # only needed when not a python install
-            candidate_paths = (os.path.relpath(path, self.installdir)
-                               for path in glob.glob(f'{self.installdir}/lib/python*/site-packages'))
-            python_paths = [path for path in candidate_paths if re.match(r'lib/python\d+\.\d+/site-packages', path)]
-
-            runtime_deps = [dep['name'] for dep in self.cfg.dependencies(runtime_only=True)]
-            use_ebpythonprefixes = 'Python' in runtime_deps and \
-                build_option('prefer_python_search_path') == EBPYTHONPREFIXES and not self.cfg['force_pythonpath']
-
-            if python_paths:
-                # Add paths unless they were already added
-                if use_ebpythonprefixes:
-                    path = ''  # EBPYTHONPREFIXES are relative to the install dir
-                    if path not in self.module_generator.added_paths_per_key[EBPYTHONPREFIXES]:
-                        lines.append(self.module_generator.prepend_paths(EBPYTHONPREFIXES, path))
-                else:
-                    for python_path in python_paths:
-                        if python_path not in self.module_generator.added_paths_per_key[PYTHONPATH]:
-                            lines.append(self.module_generator.prepend_paths(PYTHONPATH, python_path))
+        # add lines to update $PYTHONPATH or $EBPYTHONPREFIXES
+        lines.extend(self.make_module_pythonpath())
 
         modloadmsg = self.cfg['modloadmsg']
         if modloadmsg:

test/framework/toy_build.py

@@ -4238,6 +4238,69 @@ def test_eb_error(self):
             stderr = stderr.getvalue()
             self.assertTrue(regex.search(stderr), f"Pattern '{regex.pattern}' should be found in {stderr}")
 
+    def test_toy_python(self):
+        """
+        Test whether $PYTHONPATH or $EBPYTHONPREFIXES are set correctly.
+        """
+        # generate fake Python module that we can use as runtime dependency for toy
+        # (required condition for use of $EBPYTHONPREFIXES)
+        fake_mods_path = os.path.join(self.test_prefix, 'modules')
+        fake_python_mod = os.path.join(fake_mods_path, 'Python', '3.6')
+        if get_module_syntax() == 'Lua':
+            fake_python_mod += '.lua'
+            write_file(fake_python_mod, '')
+        else:
+            write_file(fake_python_mod, '#%Module')
+        self.modtool.use(fake_mods_path)
+
+        test_ecs = os.path.join(os.path.dirname(__file__), 'easyconfigs', 'test_ecs')
+        toy_ec = os.path.join(test_ecs, 't', 'toy', 'toy-0.0.eb')
+
+        test_ec_txt = read_file(toy_ec)
+        test_ec_txt += "\npostinstallcmds.append('mkdir -p %(installdir)s/lib/python3.6/site-packages')"
+        test_ec_txt += "\npostinstallcmds.append('touch %(installdir)s/lib/python3.6/site-packages/foo.py')"
+
+        test_ec = os.path.join(self.test_prefix, 'test.eb')
+        write_file(test_ec, test_ec_txt)
+        self.run_test_toy_build_with_output(ec_file=test_ec)
+
+        toy_mod = os.path.join(self.test_installpath, 'modules', 'all', 'toy', '0.0')
+        if get_module_syntax() == 'Lua':
+            toy_mod += '.lua'
+        toy_mod_txt = read_file(toy_mod)
+
+        pythonpath_regex = re.compile('^prepend.path.*PYTHONPATH.*lib/python3.6/site-packages', re.M)
+
+        self.assertTrue(pythonpath_regex.search(toy_mod_txt),
+                        f"Pattern '{pythonpath_regex.pattern}' found in: {toy_mod_txt}")
+
+        # also check when opting in to use $EBPYTHONPREFIXES instead of $PYTHONPATH
+        args = ['--prefer-python-search-path=EBPYTHONPREFIXES']
+        self.run_test_toy_build_with_output(ec_file=test_ec, extra_args=args)
+        toy_mod_txt = read_file(toy_mod)
+        # if Python is not listed as a runtime dependency then $PYTHONPATH is still used,
+        # because the Python dependency used must be aware of $EBPYTHONPREFIXES
+        # (see sitecustomize.py installed by Python easyblock)
+        self.assertTrue(pythonpath_regex.search(toy_mod_txt),
+                        f"Pattern '{pythonpath_regex.pattern}' found in: {toy_mod_txt}")
+
+        test_ec_txt += "\ndependencies = [('Python', '3.6', '', SYSTEM)]"
+        write_file(test_ec, test_ec_txt)
+        self.run_test_toy_build_with_output(ec_file=test_ec, extra_args=args)
+        toy_mod_txt = read_file(toy_mod)
+
+        ebpythonprefixes_regex = re.compile('^prepend.path.*EBPYTHONPREFIXES.*root', re.M)
+        self.assertTrue(ebpythonprefixes_regex.search(toy_mod_txt),
+                        f"Pattern '{ebpythonprefixes_regex.pattern}' found in: {toy_mod_txt}")
+
+        test_ec_txt += "\nforce_pythonpath = True"
+        write_file(test_ec, test_ec_txt)
+        self.run_test_toy_build_with_output(ec_file=test_ec)
+        toy_mod_txt = read_file(toy_mod)
+
+        self.assertTrue(pythonpath_regex.search(toy_mod_txt),
+                        f"Pattern '{pythonpath_regex.pattern}' found in: {toy_mod_txt}")
+
 
 def suite():
     """ return all the tests in this file """