failed to resolve synthetic mount registry temp directory {}

Error message

failed to resolve synthetic mount registry temp directory {}: {err}

What it means

Error "failed to resolve synthetic mount registry temp directory {}: {err}" thrown in openai/codex.

Source

Thrown at codex-rs/linux-sandbox/src/linux_run_main.rs:1344

            lock_path.display()
        );
    }
    result
}

fn synthetic_mount_marker_dir(path: &Path) -> PathBuf {
    synthetic_mount_registry_root().join(format!("{:016x}", hash_path(path)))
}

pub(crate) fn synthetic_mount_registry_root() -> PathBuf {
    static REGISTRY_ROOT: OnceLock<PathBuf> = OnceLock::new();

    REGISTRY_ROOT
        .get_or_init(|| {
            let effective_uid = unsafe { libc::geteuid() };
            let temp_dir = std::env::temp_dir();
            let temp_dir = temp_dir.canonicalize().unwrap_or_else(|err| {
                panic!(
                    "failed to resolve synthetic mount registry temp directory {}: {err}",
                    temp_dir.display()
                )
            });
            let registry_root = temp_dir.join(format!(
                "codex-bwrap-synthetic-mount-targets-{effective_uid}"
            ));
            // A registry symlink can redirect bookkeeping into a writable root
            // that does not overlap TMPDIR, bypassing its read-only mount.
            assert!(
                !registry_root.is_symlink(),
                "synthetic mount registry must not be a symlink: {}",
                registry_root.display()
            );
            registry_root
        })
        .clone()
}

View on GitHub (pinned to 339751715c)

When it happens

Trigger: Thrown at codex-rs/linux-sandbox/src/linux_run_main.rs:1344 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/0877e5d320de7325. Report an issue: GitHub.