What causes "slug must not be empty" in vectordotdev/vector?

Supply a non-empty slug: `vdev changelog new my-slug`

slug must not be empty

Error message

slug must not be empty

What it means

Raised by validate_slug when the user-supplied slug for a new changelog fragment is the empty string. The slug becomes the filename component of the fragment file, so an empty value would produce a malformed filename like '.type.md'; the guard requires a non-empty ASCII alnum/_/- component before proceeding.

Solutions

Supply a non-empty slug: `vdev changelog new <type> my-slug`
In scripts, check the variable is non-empty before invoking
If deriving the slug dynamically, add a default or fail fast when the source is empty

Example fix

// before
vdev changelog new bug_fix "$SLUG"   # SLUG=""
// after
: "${SLUG:?SLUG must be set}"
vdev changelog new bug_fix "$SLUG"

Defensive patterns

Strategy: validation

Validate before calling

if (!slug) throw new Error("slug must not be empty");

Type guard

function isNonEmptyString(v) { return typeof v === "string" && v.length > 0; }

Try / catch

try { runVdevNew(type, slug); } catch (e) { if (/slug must not be empty/.test(e.message)) slug = defaultSlug(); ... }

Prevention

Use `${VAR:?}` guards for shell-supplied slugs
Validate CLI args in wrapper scripts before exec
Fail fast in CI when derived slugs are empty

When it happens

Trigger: Invoking `vdev changelog new <type> ""` or passing an empty positional slug (e.g. a shell variable that expanded to nothing: `vdev changelog new bug_fix "$SLUG"` with SLUG unset).

Common situations: Scripted usage where the slug comes from an unset/empty environment variable or from a failed parse of some other command's output.

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 vectordotdev/vector@bdb87aeaa4 (2026-09-16). Data as JSON: /api/errors/c62c382952b1c8f3. Report an issue: GitHub.

Appendix: source

Thrown at vdev/src/commands/changelog/new.rs:78

            .with_context(|| format!("failed to run `git add {}`", file.display()))?;
        if !status.success() {
            bail!(
                "wrote {} but `git add` failed — stage it manually before running `vdev check changelog-fragments`.",
                file.display()
            );
        }

        info!("Created {}", relative(&repo_root, &file).display());
        info!("Edit the file, then run `vdev check changelog-fragments` to validate.");
        Ok(())
    }
}

/// A slug must be one filename component: ASCII alnum, `_`, or `-` only.
/// Rejects path separators, `..`, absolute paths, and anything with punctuation.
fn validate_slug(slug: &str) -> Result<()> {
    if slug.is_empty() {
        bail!("slug must not be empty");
    }
    if !slug
        .chars()
        .all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '-')
    {
        bail!(
            "invalid slug '{slug}': only ASCII letters, digits, '_', and '-' are allowed (got a path separator or punctuation?)"
        );
    }
    Ok(())
}

fn render_template(fragment_type: &FragmentType, author: &str) -> String {
    if fragment_type.breaking {
        formatdoc! {"
            # TODO one-line title

            ## Summary

View on GitHub (pinned to bdb87aeaa4)