'+ ' requires a file argument (e.g. 'fresh + file.txt'…

Error message

'+{line}' requires a file argument (e.g. 'fresh +{line} file.txt', which is equivalent to 'fresh file.txt:{line}')

What it means

A '+<line>' argument was given but no file argument followed, so there is nothing to attach the line number to. The parser bails with guidance showing the equivalent file:line form. (The DECLARED-AS/USED-AT metadata in the report refers to unrelated symbols; the error itself lives in the shown main.rs region.)

Solutions

Add the target file after the '+<line>' argument: `fresh +50 file.txt`
Use the equivalent explicit form `fresh file.txt:50`
If reading from stdin ('-'), drop the '+<line>' argument as it cannot apply
Fix scripts so an empty filename variable does not produce a bare '+line' invocation

Example fix

// before
fresh +50
// after
fresh +50 file.txt
# equivalent:
fresh file.txt:50

Defensive patterns

Strategy: validation

Validate before calling

let args: Vec<String> = std::env::args().skip(1).collect();
if args.iter().any(|a| is_plus_line_arg(a)) && args.iter().filter(|a| a.as_str() != "-").count() < 2 {
    eprintln!("'+<line>' needs a file argument");
}

Type guard

fn is_plus_line_arg(a: &str) -> bool {
    a.len() > 1 && a.starts_with('+') && a[1..].chars().all(|c| c.is_ascii_digit())
}

Try / catch

match editor::launch(args) {
    Err(e) => { eprintln!("usage: fresh +<line> <file>  (or fresh <file>:<line>)"); std::process::exit(2); }
    Ok(()) => {},
}

Prevention

Always follow +<line> with a filename
Prefer the equivalent file:line form to avoid argument-order pitfalls
Guard scripts against empty filename variables producing bare +line args
Do not combine +<line> with '-' stdin mode

When it happens

Trigger: Invoking `fresh +50` with no file arguments (or only '-' stdin placeholders) so the match on rest.iter_mut().find(...) yields None.

Common situations: Typing the line jump before remembering the filename; scripting where the filename variable is empty; piping stdin while expecting '+line' to apply to the piped buffer.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

AI-assisted analysis of sinelaw/fresh@67894ca546 (2026-09-13). Data as JSON: /api/errors/7a9ce4f5a1c0a720. Report an issue: GitHub.

Appendix: source

Thrown at crates/fresh-editor/src/main.rs:1112

    }
    match rest.iter_mut().find(|f| f.as_str() != "-") {
        Some(target) => {
            // Only annotate a file that carries no explicit location
            // yet — `fresh +50 file.txt:10` keeps the explicit 10.
            // Remote specs (`user@host:path`, `ssh://…`) take the
            // same `:line` suffix, so they work too.  A malformed
            // `ssh://` target is left alone; it errors downstream.
            let has_line = match parse_location(target) {
                Ok(ParsedLocation::Local(fl)) => fl.line.is_some(),
                Ok(ParsedLocation::Remote(rl)) => rl.line.is_some(),
                Err(_) => true,
            };
            if !has_line {
                target.push_str(&format!(":{}", line));
            }
            Ok(rest)
        }
        None => anyhow::bail!(
            "'+{line}' requires a file argument (e.g. 'fresh +{line} file.txt', \
             which is equivalent to 'fresh file.txt:{line}')"
        ),
    }
}

fn parse_file_location(input: &str) -> FileLocation {
    use std::path::{Component, Path};

    let empty = FileLocation {
        path: PathBuf::from(input),
        line: None,
        column: None,
        end_line: None,
        end_column: None,
        message: None,
    };

View on GitHub (pinned to 67894ca546)