BurntSushi/ripgrep · error

walkdir: same_file_system option not supported on this platf

Error message

walkdir: same_file_system option not supported on this platform

What it means

device_num is implemented for unix (via MetadataExt::dev) and windows (via winapi_util volume serial number). The #[cfg(not(any(unix, windows)))] stub returns Err('walkdir: same_file_system option not supported on this platform'). It is hit when same_file_system traversal is enabled on a target with no device-number concept.

Source

Thrown at crates/ignore/src/walk.rs:2187

#[cfg(unix)]
fn device_num<P: AsRef<Path>>(path: P) -> io::Result<u64> {
    use std::os::unix::fs::MetadataExt;

    path.as_ref().metadata().map(|md| md.dev())
}

#[cfg(windows)]
fn device_num<P: AsRef<Path>>(path: P) -> io::Result<u64> {
    use winapi_util::{Handle, file};

    let h = Handle::from_path_any(path)?;
    file::information(h).map(|info| info.volume_serial_number())
}

#[cfg(not(any(unix, windows)))]
fn device_num<P: AsRef<Path>>(_: P) -> io::Result<u64> {
    Err(io::Error::new(
        io::ErrorKind::Other,
        "walkdir: same_file_system option not supported on this platform",
    ))
}

#[cfg(test)]
mod tests {
    use std::ffi::OsStr;
    use std::fs::{self, File};
    use std::io::Write;
    use std::path::Path;
    use std::sync::{Arc, Mutex};

    use super::{DirEntry, WalkBuilder, WalkState};
    use crate::tests::TempDir;

    fn wfile<P: AsRef<Path>>(path: P, contents: &str) {
        let mut file = File::create(path).unwrap();

View on GitHub (pinned to 3fce3b5bb0)

Solutions

1. Disable same_file_system on the unsupported target (do not call WalkBuilder::same_file_system(true)).
2. Target a supported platform (unix or windows) if you need same-device traversal semantics.
3. Detect the target at build time and gate the same_file_system option behind cfg(any(unix, windows)).

Example fix

// before
let mut wb = WalkBuilder::new(root);
wb.same_file_system(true); // errors on wasm

// after
let mut wb = WalkBuilder::new(root);
#[cfg(any(unix, windows))]
wb.same_file_system(true);

const SAME_FS_SUPPORTED: bool = cfg!(any(unix, windows));
// only set same_file_system when true:
// #[cfg(any(unix, windows))] wb.same_file_system(true);

if cfg!(not(any(unix, windows))) {
    eprintln!("same_file_system not supported here");
    return;
}

When it happens

Trigger: Enabling WalkBuilder::same_file_system(true) (or the equivalent flag) on a non-unix/non-windows target; the walk attempts device_num to enforce the same-device constraint and gets this error.

Common situations: Cross-compiling ripgrep/ignore tooling to wasm32 with --files-with-matches and same_file_system enabled by config; a default config that turns on same_file_system unconditionally on a target that cannot support it.

Related errors

• unsupported platform
• <stdin> has no metadata
• hostname could not be found on unsupported platform

AI-assisted analysis of BurntSushi/ripgrep@3fce3b5bb0 (2026-08-06). Data as JSON: /data/errors/62f7c086ab03e878.json. Report an issue: GitHub.