Failed to create parent directory {:?} when staging custom c

Error message

Failed to create parent directory {:?} when staging custom client files: {}

What it means

Before copying `custom.txt` into the staging directory, the code ensures the staging directory exists with `std::fs::create_dir_all`. Failure to create it aborts the update with this error, which includes the target directory and the underlying io::Error.

Source

Thrown at src/platform/windows.rs:3849

                    "Failed to read metadata for custom.txt at {:?}: {}",
                    src_path,
                    e
                );
            }
        };

        if metadata.is_symlink() {
            allow_err!(remove_custom_client_staging_dir(&custom_client_staging_dir));
            bail!(
                "custom.txt at {:?} is a symlink, refusing to stage for security reasons.",
                src_path
            );
        }

        if metadata.is_file() {
            if !custom_client_staging_dir.exists() {
                if let Err(e) = std::fs::create_dir_all(custom_client_staging_dir) {
                    bail!("Failed to create parent directory {:?} when staging custom client files: {}", custom_client_staging_dir, e);
                }
            }
            let dst_path = custom_client_staging_dir.join("custom.txt");
            if let Err(e) = std::fs::copy(&src_path, &dst_path) {
                allow_err!(remove_custom_client_staging_dir(&custom_client_staging_dir));
                bail!(
                    "Failed to copy custom txt from {:?} to {:?}: {}",
                    src_path,
                    dst_path,
                    e
                );
            }
        } else {
            log::warn!(
                "custom.txt at {:?} is not a regular file, skipping.",
                src_path
            );
        }

View on GitHub (pinned to 91c9fccbb0)

Solutions

Check for a file (not directory) sitting at the staging path and remove it
Run the update elevated / fix ACLs on the staging root directory
Shorten the path or move the staging root if MAX_PATH or invalid characters are involved

Defensive patterns

Strategy: try-catch

Validate before calling

if !staging_dir.exists() {
    // ensure parent chain is creatable and no file blocks the path
    if let Some(parent) = staging_dir.parent() {
        assert!(std::fs::metadata(parent).map(|m| m.is_dir()).unwrap_or(false));
    }
}

Try / catch

if let Err(e) = std::fs::create_dir_all(&staging_dir) {
    if e.kind() == std::io::ErrorKind::PermissionDenied {
        // request elevation or choose another staging root
    }
}

Prevention

Check no regular file occupies the staging directory path
Run updates from an account with write access to the staging root
Watch for MAX_PATH problems on deeply nested staging roots

When it happens

Trigger: `custom.txt` is a regular file and the staging directory does not exist, but `create_dir_all` fails — path is invalid/too long, access denied under the staging root, or a file exists where a directory component is expected.

Common situations: Staging root on a read-only or admin-only location; a stray file occupying the directory path; MAX_PATH issues; antivirus blocking directory creation.

Understand the failure class

Background: mkdir permission denied (EACCES): failed to create directory errors explained — this error's family across 32 libraries.

Related errors

AI-assisted analysis of rustdesk/rustdesk@91c9fccbb0 (2026-09-10). Data as JSON: /api/errors/acf76bc421633faf. Report an issue: GitHub.