xai-org/grok-build · error · io::Error

{}

Error message

{}

What it means

JsonlHunkRecordWriter::write serializes each HunkRecord to JSON before appending a newline; if serde_json fails, the error is converted to io::ErrorKind::InvalidData. This is a programming/data error, not an I/O failure.

Source

Thrown at crates/codegen/xai-hunk-tracker/src/loc/mod.rs:266

            let file = tokio::fs::OpenOptions::new()
                .create(true)
                .append(true)
                .open(&self.path)
                .await?;
            self.file = Some(file);
        }
        // The `if` block above guarantees `self.file` is `Some` at this point.
        Ok(self.file.as_mut().unwrap())
    }
}

impl HunkRecordWriter for JsonlHunkRecordWriter {
    async fn write(&mut self, record: &HunkRecord) -> std::io::Result<()> {
        use tokio::io::AsyncWriteExt;

        let file = self.ensure_open().await?;
        let mut line = serde_json::to_string(record)
            .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))?;
        line.push('\n');
        file.write_all(line.as_bytes()).await?;
        Ok(())
    }

    async fn flush(&mut self) -> std::io::Result<()> {
        use tokio::io::AsyncWriteExt;

        if let Some(file) = self.file.as_mut() {
            file.flush().await?;
        }
        Ok(())
    }
}

// ---------------------------------------------------------------------------
// LocAggregate (channel-based bridge to signals)
// ---------------------------------------------------------------------------

View on GitHub (pinned to bc7f02eddd)

Solutions

1. Read the underlying serde_json error (the io error's source) to locate the failing field
2. Fix the offending field type or its Serialize implementation
3. Use serde_json::to_value in a debug assertion to fail fast at record construction

fn record_json_ok(r: &HunkRecord) -> bool {
    serde_json::to_string(r).is_ok()
}
debug_assert!(record_json_ok(record));

if let Err(e) = writer.write(&record).await {
    if e.kind() == std::io::ErrorKind::InvalidData {
        eprintln!("record failed JSON serialization: {}", e);
    }
    return Err(e.into());
}

When it happens

Trigger: Writing a HunkRecord whose fields cannot serialize to JSON (e.g. map keys that aren't strings, NaN in a float field when strict, or a custom Serialize impl that errors).

Common situations: Evolving HunkRecord with a non-JSON-safe field; passing records built from untrusted input with unexpected shapes; custom Serialize impls returning Err.

Related errors

• Compaction checkpoint file corrupt: {checkpoint_path}. Canno
• {}
• failed to build request: {e}
• response parse error: {e}
• failed to read {}: {e}

AI-assisted analysis of xai-org/grok-build@bc7f02eddd (2026-08-31). Data as JSON: /api/errors/fa2c6a749f25a017. Report an issue: GitHub.