correctly deal with easyblocks that still use deprecated make_module_req_guess method: remove environment variables if they're not present in guesses

easybuild/framework/easyblock.py

@@ -1681,12 +1681,12 @@ def make_module_req(self):
 
         if self.make_module_req_guess.__qualname__ != "EasyBlock.make_module_req_guess":
             # Deprecated make_module_req_guess method used in child Easyblock
-            # Update environment with custom make_module_req_guess
+            # adjust environment with custom make_module_req_guess
             self.log.deprecated(
                 "make_module_req_guess() is deprecated, use EasyBlock.module_load_environment instead.",
                 "6.0",
             )
-            self.module_load_environment.update(self.make_module_req_guess())
+            self.module_load_environment.replace(self.make_module_req_guess())
 
         # Expand and inject path-like environment variables into module file
         env_var_requirements = {

easybuild/tools/modules.py

@@ -351,6 +351,12 @@ def update(self, new_env):
         except AttributeError as err:
             raise EasyBuildError("Cannot update ModuleLoadEnvironment from a non-dict variable") from err
 
+    def replace(self, new_env):
+        """Replace contents of environment with given dictionary"""
+        for var in self.vars:
+            self.remove(var)
+        self.update(new_env)
+
     def remove(self, var_name):
         """
         Remove ModuleEnvironmentVariable attribute from instance

test/framework/modules.py

@@ -1747,6 +1747,19 @@ def test_module_load_environment(self):
         self.assertFalse(hasattr(mod_load_env, 'TEST_VARTYPE'))
         mod_load_env.remove('NONEXISTENT')
 
+        # test replacing of env vars
+        env_vars = sorted(mod_load_env.as_dict.keys())
+        expected = ['ACLOCAL_PATH', 'CLASSPATH', 'CMAKE_LIBRARY_PATH', 'CMAKE_PREFIX_PATH', 'GI_TYPELIB_PATH',
+                    'LD_LIBRARY_PATH', 'LIBRARY_PATH', 'MANPATH', 'PATH', 'PKG_CONFIG_PATH', 'TEST_NEW_VAR',
+                    'TEST_STR', 'TEST_VAR', 'XDG_DATA_DIRS']
+        self.assertEqual(env_vars, expected)
+
+        mod_load_env.replace({'FOO': 'foo', 'BAR': 'bar'})
+        env_vars = sorted(mod_load_env.as_dict.keys())
+        self.assertEqual(env_vars, ['BAR', 'FOO'])
+        self.assertEqual(mod_load_env.BAR.contents, ['bar'])
+        self.assertEqual(mod_load_env.FOO.contents, ['foo'])
+
         # test aliases
         aliases = {
             'ALIAS1': ['ALIAS_VAR11', 'ALIAS_VAR12'],