fixup! Add --assert-config option

Author: hroncok

src/tox_current_env/hooks4.py

@@ -79,7 +79,12 @@ def tox_add_core_config(core_conf, state):
     opt = state.conf.options
 
     if opt.assert_config and not state.conf.src_path.exists():
-        raise LookupError("tox configuration not found.")
+        raise LookupError(
+            "tox configuration not found. "
+            "To use tox, please ensure tox configuration is located in current directory "
+            "(in tox.ini, setup.cfg, pyproject.toml, or tox.toml). "
+            "See https://tox.wiki/en/latest/config.html for details."
+        )
 
     if opt.current_env or opt.print_deps_to or opt.print_extras_to or opt.print_dependency_groups_to:
         # We do not want to install the main package.