astral-sh/ruff · error · anyhow::Error

Invalid alias for module '{module}': alias normalizes to '__

Error message

Invalid alias for module '{module}': alias normalizes to '__debug__', which is not allowed.

What it means

Error "Invalid alias for module '{module}': alias normalizes to '__debug__', which is not allowed." thrown in astral-sh/ruff.

Source

Thrown at crates/ruff_workspace/src/options.rs:1794

            None => flake8_import_conventions::settings::default_aliases(preview),
        };
        if let Some(extend_aliases) = self.extend_aliases {
            aliases.extend(
                extend_aliases
                    .into_iter()
                    .map(|(module, alias)| (module.into_string(), alias.into_string())),
            );
        }

        let mut normalized_aliases: FxHashMap<String, String> = FxHashMap::default();
        #[expect(
            clippy::iter_over_hash_type,
            reason = "every invalid alias is rejected, regardless of which one is reported first"
        )]
        for (module, alias) in aliases {
            let normalized_alias = alias.nfkc().collect::<String>();
            if normalized_alias == "__debug__" {
                anyhow::bail!(
                    "Invalid alias for module '{module}': alias normalizes to '__debug__', \
                    which is not allowed."
                );
            }
            normalized_aliases.insert(module, normalized_alias);
        }

        let banned_aliases = self.banned_aliases.unwrap_or_else(|| {
            flake8_import_conventions::settings::default_banned_aliases(preview)
        });

        Ok(flake8_import_conventions::settings::Settings {
            aliases: normalized_aliases,
            banned_aliases,
            banned_from: self.banned_from.unwrap_or_default(),
        })
    }
}

View on GitHub (pinned to 672bb4edf0)

When it happens

Trigger: Thrown at crates/ruff_workspace/src/options.rs:1794 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of astral-sh/ruff@672bb4edf0 (2026-08-16). Data as JSON: /api/errors/8bdbd62aab834ba5. Report an issue: GitHub.