What causes "Invalid request: Empty request line URI" in epi052/feroxbuster?

Ensure a non-empty path follows the method on the first line (at minimum '/')

Invalid request: Empty request line URI

Error message

Invalid request: Empty request line URI

What it means

Thrown by parse_request_file when the URI token on the request line is present but empty. After the method is read, the next token is checked; an empty string here means the request line is malformed (e.g. trailing space with no path).

Solutions

Ensure a non-empty path follows the method on the first line (at minimum '/')
Normalize the request line with a single space between METHOD, URI and VERSION (e.g. tr -s ' ' on the first line)
Check for invisible characters (tabs/CR) that consume the URI token; strip or rewrite the first line

Example fix

// before
"GET   HTTP/1.1"
// after
"GET / HTTP/1.1"

Defensive patterns

Strategy: validation

Validate before calling

fn request_line_uri_nonempty(raw: &str) -> Result<(), String> {
    let line = raw.lines().next().unwrap_or("");
    let parts: Vec<&str> = line.split_whitespace().collect();
    if parts.len() >= 2 && !parts[1].is_empty() {
        Ok(())
    } else {
        Err("request line URI token missing or empty".into())
    }
}

Prevention

Normalize whitespace in the request line (single spaces, no tabs)
Use an editor that trims trailing spaces, or run sed to clean the file
Always include an explicit path ('/') in generated requests

When it happens

Trigger: A request line like 'GET HTTP/1.1' with double spaces or a method followed by trailing whitespace, so uri.is_empty() evaluates true after whitespace splitting.

Common situations: Files edited in editors that preserve trailing spaces; requests reconstructed by concatenation scripts that drop the path; template request files with an unfilled URI placeholder.

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

Related errors

AI-assisted analysis of epi052/feroxbuster@1f595dab5c (2026-09-13). Data as JSON: /api/errors/fd8ff9286a57d1ee. Report an issue: GitHub.

Appendix: source

Thrown at src/config/utils.rs:510

        bail!("Invalid request: Missing method");
    };

    if method.is_empty() {
        bail!("Invalid request: Empty method");
    }

    let method = method.to_string();

    if !config.methods.contains(&method) {
        config.methods.push(method);
    }

    let Some(uri) = request_parts.next() else {
        bail!("Invalid request: Missing request line URI");
    };

    if uri.is_empty() {
        bail!("Invalid request: Empty request line URI");
    }

    for mut line in head_parts {
        line = line.trim_matches('\r').trim();

        if line.is_empty() {
            break; // Empty line signals the end of headers
        }

        let Ok((name, value)) = split_header(line) else {
            log::warn!("Invalid header: {line}");
            continue;
        };

        if name.is_empty() {
            log::warn!("Invalid header name: {line}");
            continue;
        }

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