FAQ

Common subgraph indexing errors

• Mapping terminated before handling trigger: oneshot canceled: caused by WASM runtime panics. Newer apiVersions may have a more helpful error message.

  Common reasons include:

  • Using array forEach, which is not supported.

  • Loading an entity with a null ID.

  • Setting a field to null when the field is non-nullable in the schema.

• wasm trap: unreachable wasm: caused by WASM executing code that should not be reachable.

  Common reasons include:

  • Using array forEach or map, which are not supported.

  • Array access out of bounds.

• Subgraph panicked with message: called `Result::unwrap()` on an `Err` value: MemoryAccessError { _private: () }: caused by various reasons around accessing state in handlers. A common reason is using more than 2 GB of WASM memory, which can be solved by reducing the memory footprint of the handlers.