Merge pull request #3633 from Flamefire/mlUnuse

Avoid module call for unuse() for Lmod and set $MODULEPATH directly

Author: boegel

easybuild/tools/modules.py

@@ -1443,6 +1443,21 @@ def use(self, path, priority=None):
                                ('<unset>' if cur_mod_path is None else cur_mod_path, new_mod_path))
                 os.environ['MODULEPATH'] = new_mod_path
 
+    def unuse(self, path):
+        """Remove a module path"""
+        # We can simply remove the path from MODULEPATH to avoid the costly module call
+        cur_mod_path = os.environ.get('MODULEPATH')
+        if cur_mod_path is not None:
+            # Removing the last entry unsets the variable
+            if cur_mod_path == path:
+                self.log.debug('Changing MODULEPATH from %s to <unset>' % cur_mod_path)
+                del os.environ['MODULEPATH']
+            else:
+                new_mod_path = ':'.join(p for p in cur_mod_path.split(':') if p != path)
+                if new_mod_path != cur_mod_path:
+                    self.log.debug('Changing MODULEPATH from %s to %s' % (cur_mod_path, new_mod_path))
+                    os.environ['MODULEPATH'] = new_mod_path
+
     def prepend_module_path(self, path, set_mod_paths=True, priority=None):
         """
         Prepend given module path to list of module paths, or bump it to 1st place.

test/framework/modules.py

@@ -1157,11 +1157,11 @@ def test_module_use_unuse(self):
 
         self.assertFalse(test_dir1 in os.environ.get('MODULEPATH', ''))
         self.modtool.use(test_dir1)
-        self.assertTrue(os.environ.get('MODULEPATH', '').startswith('%s:' % test_dir1))
+        self.assertTrue(os.environ['MODULEPATH'].startswith('%s:' % test_dir1))
         self.modtool.use(test_dir2)
-        self.assertTrue(os.environ.get('MODULEPATH', '').startswith('%s:' % test_dir2))
+        self.assertTrue(os.environ['MODULEPATH'].startswith('%s:' % test_dir2))
         self.modtool.use(test_dir3)
-        self.assertTrue(os.environ.get('MODULEPATH', '').startswith('%s:' % test_dir3))
+        self.assertTrue(os.environ['MODULEPATH'].startswith('%s:' % test_dir3))
 
         # make sure the right test module is loaded
         self.modtool.load(['test'])
@@ -1193,8 +1193,9 @@ def test_module_use_unuse(self):
         self.assertEqual(os.getenv('TEST123'), 'two')
         self.modtool.unload(['test'])
 
-        # check whether prepend with priority actually works (only for Lmod)
+        # Tests for Lmod only
         if isinstance(self.modtool, Lmod):
+            # check whether prepend with priority actually works (priority is specific to Lmod)
             self.modtool.use(test_dir1, priority=100)
             self.modtool.use(test_dir3)
             self.assertTrue(os.environ['MODULEPATH'].startswith('%s:%s:%s:' % (test_dir2, test_dir1, test_dir3)))
@@ -1212,6 +1213,28 @@ def test_module_use_unuse(self):
             self.assertEqual(os.getenv('TEST123'), 'three')
             self.modtool.unload(['test'])
 
+            # Check load and unload for a single path when it is the only one
+            # Only for Lmod as we have some shortcuts for avoiding the module call there
+            old_module_path = os.environ['MODULEPATH']
+            del os.environ['MODULEPATH']
+            self.modtool.use(test_dir1)
+            self.assertEqual(os.environ['MODULEPATH'], test_dir1)
+            self.modtool.unuse(test_dir1)
+            self.assertFalse('MODULEPATH' in os.environ)
+            os.environ['MODULEPATH'] = old_module_path  # Restore
+
+            # Using an empty path still works (technically) (Lmod only, ignored by Tcl)
+            old_module_path = os.environ['MODULEPATH']
+            self.modtool.use('')
+            self.assertEqual(os.environ['MODULEPATH'], ':' + old_module_path)
+            self.modtool.unuse('')
+            self.assertEqual(os.environ['MODULEPATH'], old_module_path)
+            # Even works when the whole path is empty
+            os.environ['MODULEPATH'] = ''
+            self.modtool.unuse('')
+            self.assertFalse('MODULEPATH' in os.environ)
+            os.environ['MODULEPATH'] = old_module_path  # Restore
+
     def test_module_use_bash(self):
         """Test whether effect of 'module use' is preserved when a new bash session is started."""
         # this test is here as check for a nasty bug in how the modules tool is deployed