tracel-ai/burn · error

Invalid regex pattern

Error message

Invalid regex pattern

What it means

Regex validation guard in `with_remap_pattern`: the `from` string is compiled as a regex for key remapping; an invalid pattern makes `Regex::new` fail and the builder panics instead of silently accepting a broken remapper.

Source

Thrown at crates/burn-store/src/burnpack.rs:303

    /// Set key remapper for tensor name transformations during loading
    #[cfg(feature = "std")]
    pub fn remap(mut self, remapper: KeyRemapper) -> Self {
        self.remapper = remapper;
        self
    }

    /// Add a single regex pattern for key remapping
    #[cfg(feature = "std")]
    pub fn with_remap_pattern<S1, S2>(mut self, from: S1, to: S2) -> Self
    where
        S1: AsRef<str>,
        S2: Into<String>,
    {
        self.remapper = self
            .remapper
            .add_pattern(from.as_ref(), to.into())
            .expect("Invalid regex pattern");
        self
    }

    /// Set the path filter
    pub fn filter(mut self, filter: PathFilter) -> Self {
        self.filter = Some(filter);
        self
    }

    /// Get the bytes after writing (only valid for bytes mode after collecting)
    pub fn get_bytes(&self) -> Result<Bytes, PackError> {
        // `collect_from` caches the written bytes back into `self.mode` for bytes mode.
        match &self.mode {
            StoreMode::Bytes(Some(bytes)) => Ok(bytes.clone()),
            _ => Err(PackError::IoError("No bytes available".into())),
        }
    }

View on GitHub (pinned to d16f7ba2ed)

Solutions

1. Validate the pattern with `Regex::new` before passing it
2. Fix escaping of regex metacharacters (e.g., `.`, `(`, `*`) in the pattern
3. Use `add_pattern` with error handling for fallible construction

When it happens

Trigger: Thrown at crates/burn-store/src/burnpack.rs:303 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of tracel-ai/burn@d16f7ba2ed (2026-09-05). Data as JSON: /api/errors/d1292eaa683bb76d. Report an issue: GitHub.