Do not create module in sanity check of extensioneasyblock

Using the "fake module environment" creates a module file.
However in `--module-only` setups we want to use the real module file instead.

This also avoids potentially loading the real AND the fake module.

Author: Flamefire

easybuild/framework/easyblock.py

@@ -2408,6 +2408,31 @@ def fake_module_environment(self, extra_modules=None, with_build_deps=False):
             if fake_mod_data:
                 self.clean_up_fake_module(fake_mod_data)
 
+    @contextmanager
+    def sanity_check_module_environment(self, extra_modules=None, with_build_deps=False, check_loaded=True):
+        """Load/Unload module for performing sanity checks"""
+        if self.sanity_check_module_loaded and check_loaded:
+            raise EasyBuildError("Sanity check module is already loaded and must not be loaded again")
+
+        if self.sanity_check_module_loaded:
+            unload_module = False
+        else:
+            if with_build_deps:
+                # load modules for build dependencies as extra modules
+                extra_modules = [dep['short_mod_name'] for dep in self.cfg.dependencies(build_only=True)]
+            self.sanity_check_load_module(extension=self.is_extension, extra_modules=extra_modules)
+            unload_module = True
+
+        try:
+            yield
+        finally:
+            # cleanup (unload fake module, remove fake module dir)
+            if unload_module:
+                if self.fake_mod_data:
+                    self.clean_up_fake_module(self.fake_mod_data)
+                    self.fake_mod_data = None
+                self.sanity_check_module_loaded = False
+
     def guess_start_dir(self):
         """
         Return the directory where to start the whole configure/make/make install cycle from

easybuild/framework/extensioneasyblock.py

@@ -181,7 +181,7 @@ def sanity_check_step(self, exts_filter=None, custom_paths=None, custom_commands
         # take into account that module may already be loaded earlier in sanity check
         if not (self.sanity_check_module_loaded or self.is_extension or self.dry_run):
             for extra_modules in lists_of_extra_modules:
-                with self.fake_module_environment(extra_modules=extra_modules):
+                with self.sanity_check_module_environment(extra_modules=extra_modules):
                     if extra_modules:
                         info_msg = f"Running extension sanity check with extra modules: {', '.join(extra_modules)}"
                         self.log.info(info_msg)