rust-lang/rust-analyzer · error · io::Error

error creating directory {path:?}: {e}

Error message

error creating directory {path:?}: {e}

What it means

An `io::Error` formatting string in `stdx`'s tempfile helper `create`: the loop joins a prefix, PID, and an internal atomic counter into a candidate path and calls the caller's `create` with `create_new(true)`; when the create callback fails for a non-collision reason, the error is wrapped with the candidate `{path}`. The input at fault is the OS-level directory/file creation under the system temp dir (permissions, disk full, or the specific callback's open options).

Source

Thrown at crates/stdx/src/tempfile.rs:98

    static INTERNAL_COUNTER: AtomicU32 = AtomicU32::new(0);

    pub(super) fn create<T>(
        prefix: &str,
        mut create: impl FnMut(OpenOptions, &Path) -> io::Result<T>,
    ) -> io::Result<(T, PathBuf)> {
        let temp_dir = std::env::temp_dir().canonicalize()?;
        let pid = std::process::id();
        loop {
            let path = temp_dir.join(format!(
                "{prefix}{pid:x}-{:x}",
                INTERNAL_COUNTER.fetch_add(1, Ordering::AcqRel),
            ));
            let mut open_options = OpenOptions::new();
            open_options.create_new(true);
            match create(open_options, &path) {
                Err(e) if e.kind() == ErrorKind::AlreadyExists => {}
                Err(e) => {
                    return Err(io::Error::new(
                        e.kind(),
                        format!("error creating directory {path:?}: {e}"),
                    ));
                }
                Ok(file) => {
                    return Ok((file, path));
                }
            }
        }
    }
}

#[cfg(any(
    target_os = "linux",
    target_os = "freebsd",
    target_os = "openbsd",
    target_os = "netbsd",
))]

View on GitHub (pinned to e8f7e90aa3)

Solutions

1. Check that the system temp dir (`std::env::temp_dir`) is writable and not full
2. If the failure is `AlreadyExists` from a non-atomic helper, the retry loop only covers collisions produced by this helper — ensure custom create callbacks use `create_new(true)` so the loop can retry on collision
3. Clear stale temp files matching the prefix that may block creation
4. Surface the underlying `e` in the message to identify the exact OS error kind

When it happens

Trigger: Thrown at crates/stdx/src/tempfile.rs:98 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of rust-lang/rust-analyzer@e8f7e90aa3 (2026-09-03). Data as JSON: /api/errors/d82a4ed2b811b657. Report an issue: GitHub.