Merge pull request #3557 from Flamefire/avoid_module_use

avoid running expensive 'module use' command when using Lmod as modules tool, update $MODULEPATH directly instead

Author: boegel

easybuild/tools/modules.py

@@ -1428,7 +1428,20 @@ def use(self, path, priority=None):
         if priority:
             self.run_module(['use', '--priority', str(priority), path])
         else:
-            self.run_module(['use', path])
+            # LMod allows modifying MODULEPATH directly. So do that to avoid the costly module use
+            # unless priorities are in use already
+            if os.environ.get('__LMOD_Priority_MODULEPATH'):
+                self.run_module(['use', path])
+            else:
+                cur_mod_path = os.environ.get('MODULEPATH')
+                if cur_mod_path is None:
+                    new_mod_path = path
+                else:
+                    new_mod_path = [path] + [p for p in cur_mod_path.split(':') if p != path]
+                    new_mod_path = ':'.join(new_mod_path)
+                self.log.debug('Changing MODULEPATH from %s to %s' %
+                               ('<unset>' if cur_mod_path is None else cur_mod_path, new_mod_path))
+                os.environ['MODULEPATH'] = new_mod_path
 
     def prepend_module_path(self, path, set_mod_paths=True, priority=None):
         """

test/framework/modules.py

@@ -1142,24 +1142,75 @@ def test_module_caches(self):
         self.assertEqual(mod.MODULE_AVAIL_CACHE, {})
         self.assertEqual(mod.MODULE_SHOW_CACHE, {})
 
-    def test_module_use(self):
-        """Test 'module use'."""
+    def test_module_use_unuse(self):
+        """Test 'module use' and 'module unuse'."""
         test_dir1 = os.path.join(self.test_prefix, 'one')
         test_dir2 = os.path.join(self.test_prefix, 'two')
         test_dir3 = os.path.join(self.test_prefix, 'three')
 
+        for subdir in ('one', 'two', 'three'):
+            modtxt = '\n'.join([
+                '#%Module',
+                "setenv TEST123 %s" % subdir,
+            ])
+            write_file(os.path.join(self.test_prefix, subdir, 'test'), modtxt)
+
         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.modtool.use(test_dir2)
+        self.assertTrue(os.environ.get('MODULEPATH', '').startswith('%s:' % test_dir2))
+        self.modtool.use(test_dir3)
+        self.assertTrue(os.environ.get('MODULEPATH', '').startswith('%s:' % test_dir3))
+
+        # make sure the right test module is loaded
+        self.modtool.load(['test'])
+        self.assertEqual(os.getenv('TEST123'), 'three')
+        self.modtool.unload(['test'])
+
+        self.modtool.unuse(test_dir3)
+        self.assertFalse(test_dir3 in os.environ.get('MODULEPATH', ''))
+
+        self.modtool.load(['test'])
+        self.assertEqual(os.getenv('TEST123'), 'two')
+        self.modtool.unload(['test'])
+
+        self.modtool.unuse(test_dir2)
+        self.assertFalse(test_dir2 in os.environ.get('MODULEPATH', ''))
+
+        self.modtool.load(['test'])
+        self.assertEqual(os.getenv('TEST123'), 'one')
+        self.modtool.unload(['test'])
+
+        self.modtool.unuse(test_dir1)
+        self.assertFalse(test_dir1 in os.environ.get('MODULEPATH', ''))
 
         # also test use with high priority
         self.modtool.use(test_dir2, priority=10000)
         self.assertTrue(os.environ['MODULEPATH'].startswith('%s:' % test_dir2))
 
+        self.modtool.load(['test'])
+        self.assertEqual(os.getenv('TEST123'), 'two')
+        self.modtool.unload(['test'])
+
         # check whether prepend with priority actually works (only for Lmod)
         if isinstance(self.modtool, Lmod):
+            self.modtool.use(test_dir1, priority=100)
             self.modtool.use(test_dir3)
-            self.assertTrue(os.environ['MODULEPATH'].startswith('%s:%s:' % (test_dir2, test_dir3)))
+            self.assertTrue(os.environ['MODULEPATH'].startswith('%s:%s:%s:' % (test_dir2, test_dir1, test_dir3)))
+            self.modtool.load(['test'])
+            self.assertEqual(os.getenv('TEST123'), 'two')
+            self.modtool.unload(['test'])
+
+            self.modtool.unuse(test_dir2)
+            self.modtool.load(['test'])
+            self.assertEqual(os.getenv('TEST123'), 'one')
+            self.modtool.unload(['test'])
+
+            self.modtool.unuse(test_dir1)
+            self.modtool.load(['test'])
+            self.assertEqual(os.getenv('TEST123'), 'three')
+            self.modtool.unload(['test'])
 
     def test_module_use_bash(self):
         """Test whether effect of 'module use' is preserved when a new bash session is started."""