jdx/mise · error · eyre::Report

directive requires one argument

Error message

directive requires one argument

What it means

parse_argument, the shared tokenizer for go.work use entries and go.mod module directives, bails when the argument substring handed to it is empty. It is the empty-argument guard at the front of the parser: a directive keyword is present but no path/name token follows it once the line has been comment-stripped and trimmed.

Source

Thrown at src/task/workspace/go.rs:181

        if module_path.replace(parsed).is_some() {
            bail!("Go module metadata contains multiple module directives");
        }
    }

    module_path.ok_or_else(|| eyre::eyre!("Go module metadata is missing a module directive"))
}

fn directive_arguments<'a>(line: &'a str, directive: &str) -> Option<&'a str> {
    let rest = line.strip_prefix(directive)?;
    if !rest.starts_with(char::is_whitespace) {
        return None;
    }
    Some(rest.trim())
}

fn parse_argument(value: &str) -> Result<String> {
    if value.is_empty() {
        bail!("directive requires one argument");
    }
    if let Some(value) = value.strip_prefix('"') {
        let Some(value) = value.strip_suffix('"') else {
            bail!("unterminated interpreted Go string");
        };
        return unescape_go_string(value);
    }
    if let Some(value) = value.strip_prefix('`') {
        let Some(value) = value.strip_suffix('`') else {
            bail!("unterminated raw Go string");
        };
        if value.contains('`') {
            bail!("unexpected raw Go string delimiter");
        }
        return Ok(value.to_string());
    }
    if value.split_whitespace().count() != 1 {
        bail!("directive requires exactly one argument");

View on GitHub (pinned to 6f52dcdf99)

Solutions

1. Give the directive its single argument: `use ./api` or `module example.com/pkg`
2. If the directive is unwanted, delete the whole line rather than emptying it
3. Prefer `go work edit` / `go mod edit` over manual text surgery

Example fix

# before (go.work)
use 

# after
use ./api

fn directive_has_argument(line: &str, keyword: &str) -> bool {
    match line.strip_prefix(keyword) {
        Some(rest) => !rest.trim().is_empty(),
        None => true, // not this directive
    }
}

fn all_directives_have_arguments(contents: &str) -> bool {
    contents.lines().all(|raw| {
        let line = raw.split("//").next().unwrap_or("").trim();
        line != "use" && line != "module"
    })
}

Err(report) if report.to_string().contains("directive requires one argument") => {
    // locate the bare keyword line via the wrapped context ("invalid ... directive on line N") and remove it
    remove_bare_directive_lines(&mut contents);
}

When it happens

Trigger: A `use` or `module` directive whose argument portion is blank after `//` comment stripping and trimming (e.g. a line reduced to the keyword plus separating whitespace by an aggressive edit); programmatic callers passing a pre-trimmed empty token; inside a `use (...)` block, an entry line that carries no argument token.

Common situations: Hand-edits that delete the path but keep the keyword and its whitespace; scripts that rewrite directive arguments to empty strings instead of removing the line; truncated edits during merge conflict resolution.

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

• directive requires exactly one argument
• unterminated use block
• unterminated interpreted Go string
• unterminated raw Go string
• unexpected raw Go string delimiter

AI-assisted analysis of jdx/mise@6f52dcdf99 (2026-08-22). Data as JSON: /api/errors/f89d045faf541071. Report an issue: GitHub.