tracel-ai/burn · error

Invalid regex pattern

Error message

Invalid regex pattern

What it means

Regex validation guard in `PytorchStore::with_key_remapping`: the `from_pattern` is compiled as a regex for tensor-name remapping during load; an invalid pattern panics instead of producing a silently non-matching remapper.

Source

Thrown at crates/burn-store/src/pytorch/store.rs:249

    /// Add a regex pattern to remap tensor names during load.
    ///
    /// # Example
    /// ```rust,no_run
    /// # use burn_store::PytorchStore;
    /// let store = PytorchStore::from_file("model.pth")
    ///     .with_key_remapping(r"^encoder\.", "transformer.encoder.")  // encoder.X -> transformer.encoder.X
    ///     .with_key_remapping(r"\.gamma$", ".weight");               // X.gamma -> X.weight
    /// ```
    pub fn with_key_remapping(
        mut self,
        from_pattern: impl AsRef<str>,
        to_pattern: impl Into<String>,
    ) -> Self {
        self.remapper = self
            .remapper
            .add_pattern(from_pattern, to_pattern)
            .expect("Invalid regex pattern");
        self
    }

    /// Set whether to validate tensors during loading (default: true).
    pub fn validate(mut self, validate: bool) -> Self {
        self.validate = validate;
        self
    }

    /// Allow partial loading of tensors (continue even if some tensors are missing).
    pub fn allow_partial(mut self, allow: bool) -> Self {
        self.allow_partial = allow;
        self
    }

    /// Skip enum variant names when matching tensor paths (default: true).
    ///
    /// When enabled, tensor paths from PyTorch that don't include enum variants

View on GitHub (pinned to d16f7ba2ed)

Solutions

1. Pre-validate the pattern with `Regex::new`
2. Fix regex escapes (e.g., `\.` for literal dots) in the pattern
3. Test the pattern against expected key names before building the store

When it happens

Trigger: Thrown at crates/burn-store/src/pytorch/store.rs:249 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/7e68d65d6cb2b5bd. Report an issue: GitHub.