openai/codex · error · std::io::Error

WouldBlock

WouldBlock

Error message

could not acquire exclusive lock on history file after multiple attempts

What it means

Error "could not acquire exclusive lock on history file after multiple attempts" thrown in openai/codex.

Source

Thrown at codex-rs/message-history/src/lib.rs:181

            match history_file.try_lock() {
                Ok(()) => {
                    // While holding the exclusive lock, write the full line.
                    // We do not open the file with `append(true)` on Windows, so ensure the
                    // cursor is positioned at the end before writing.
                    history_file.seek(SeekFrom::End(0))?;
                    history_file.write_all(line.as_bytes())?;
                    history_file.flush()?;
                    enforce_history_limit(&mut history_file, history_max_bytes)?;
                    return Ok(());
                }
                Err(std::fs::TryLockError::WouldBlock) => {
                    std::thread::sleep(RETRY_SLEEP);
                }
                Err(e) => return Err(e.into()),
            }
        }

        Err(std::io::Error::new(
            std::io::ErrorKind::WouldBlock,
            "could not acquire exclusive lock on history file after multiple attempts",
        ))
    })
    .await??;

    Ok(())
}

/// Trim the history file to honor `max_bytes`, dropping the oldest lines while holding
/// the write lock so the newest entry is always retained. When the file exceeds the
/// hard cap, it rewrites the remaining tail to a soft cap to avoid trimming again
/// immediately on the next write.
fn enforce_history_limit(file: &mut File, max_bytes: Option<usize>) -> Result<()> {
    let Some(max_bytes) = max_bytes else {
        return Ok(());
    };

View on GitHub (pinned to 339751715c)

When it happens

Trigger: Thrown at codex-rs/message-history/src/lib.rs:181 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of openai/codex@339751715c (2026-08-25). Data as JSON: /api/errors/64dfe0d16f6f691f. Report an issue: GitHub.