reinstate fallback to ModulesTool.module_wrapper_exists in ModulesToo…

…l.exist (fixes easybuilders#3335)

easybuild/tools/modules.py

@@ -487,10 +487,7 @@ def module_wrapper_exists(self, mod_name, modulerc_fn='.modulerc', mod_wrapper_r
         """
         Determine whether a module wrapper with specified name exists.
         Only .modulerc file in Tcl syntax is considered here.
-        DEPRECATED. Use exists()
         """
-        self.log.deprecated('module_wrapper_exists is unreliable and should no longer be used. ' +
-                            'Use exists instead to check for an existing module or alias.', '5.0')
 
         if mod_wrapper_regex_template is None:
             mod_wrapper_regex_template = "^[ ]*module-version (?P<wrapped_mod>[^ ]*) %s$"
@@ -590,6 +587,19 @@ def mod_exists_via_show(mod_name):
                 self.log.debug("checking whether hidden module %s exists via 'show'..." % mod_name)
                 mod_exists = mod_exists_via_show(mod_name)
 
+            # if no module file was found, check whether specified module name can be a 'wrapper' module...
+            # this fallback mechanism is important when using a hierarchical module naming scheme,
+            # where "full" module names (like Core/Java/11) are used to check whether modules exist already;
+            # Lmod will report module wrappers as non-existent when full module name is used,
+            # see https://github.com/TACC/Lmod/issues/446
+            if not mod_exists:
+                self.log.debug("Module %s not found via module avail/show, checking whether it is a wrapper", mod_name)
+                wrapped_mod = self.module_wrapper_exists(mod_name)
+                if wrapped_mod is not None:
+                    # module wrapper only really exists if the wrapped module file is also available
+                    mod_exists = wrapped_mod in avail_mod_names or mod_exists_via_show(wrapped_mod)
+                    self.log.debug("Result for existence check of wrapped module %s: %s", wrapped_mod, mod_exists)
+
             self.log.debug("Result for existence check of %s module: %s", mod_name, mod_exists)
 
             mods_exist.append(mod_exists)
@@ -1407,7 +1417,7 @@ def prepend_module_path(self, path, set_mod_paths=True, priority=None):
     def module_wrapper_exists(self, mod_name):
         """
         Determine whether a module wrapper with specified name exists.
-        DEPRECATED. Use exists()
+        First check for wrapper defined in .modulerc.lua, fall back to also checking .modulerc (Tcl syntax).
         """
         res = None
 

test/framework/modules.py

@@ -318,9 +318,12 @@ def test_exist(self):
 
         self.assertTrue('Core/Java/1.8.0_181' in self.modtool.available())
         self.assertEqual(self.modtool.exist(['Core/Java/1.8.0_181']), [True])
-        # module-version only works for EnvironmentModules(C) as LMod and EnvironmentModulesTcl would need updating
-        # to full path, see https://github.com/TACC/Lmod/issues/446
-        if isinstance(self.modtool, Lmod) or self.modtool.__class__ == EnvironmentModulesTcl:
+        # module-version only works for EnvironmentModules(C), not with EnvironmentModulesTcl;
+        # for Lmod, there's a workaround to ensure that module wrappers/aliases are recognized when they're
+        # being checked with the full module name (see https://github.com/TACC/Lmod/issues/446);
+        # that's necessary when using a hierarchical module naming scheme,
+        # see https://github.com/easybuilders/easybuild-framework/issues/3335
+        if self.modtool.__class__ == EnvironmentModulesTcl:
             self.assertEqual(self.modtool.exist(['Core/Java/1.8', 'Core/Java/site_default']), [False, False])
         else:
             self.assertEqual(self.modtool.exist(['Core/Java/1.8', 'Core/Java/site_default']), [True, True])
@@ -354,8 +357,8 @@ def test_exist(self):
             shutil.move(java_mod_dir, os.path.join(self.test_prefix, 'Core', 'Java'))
             self.assertTrue('Core/Java/1.8.0_181' in self.modtool.available())
             self.assertEqual(self.modtool.exist(['Core/Java/1.8.0_181']), [True])
-            self.assertEqual(self.modtool.exist(['Core/Java/1.8']), [False])
-            self.assertEqual(self.modtool.exist(['Core/Java/site_default']), [False])
+            self.assertEqual(self.modtool.exist(['Core/Java/1.8']), [True])
+            self.assertEqual(self.modtool.exist(['Core/Java/site_default']), [True])
 
         # Test alias in home directory .modulerc
         if isinstance(self.modtool, Lmod) and StrictVersion(self.modtool.version) >= StrictVersion('7.0'):