gohugoio/hugo · error

invalid modules list

Error message

invalid modules list: %q

What it means

collectModulesTXT parses _vendor/modules.txt line by line; each line must have exactly two whitespace fields (module path and version). Any line with != 2 fields aborts vendor parsing with the offending filename. The file is normally generated by `go mod vendor`, so a malformed line implies manual edits or corruption.

Solutions

1. Regenerate the vendor directory: `hugo mod vendor` (or `go mod vendor`) to produce a canonical modules.txt.
2. If you must hand-edit, ensure every non-comment line is exactly `path version`.
3. Inspect the file: `cat _vendor/modules.txt` and find the line with the wrong field count.
4. Remove the stale _vendor dir entirely if vendoring is not intended (`rm -rf _vendor`).

Example fix

// before: a malformed line in _vendor/modules.txt
# github.com/x/y v1.2.3 extra-note
github.com/x/y v1.2.3
// after: regenerate
rm -rf _vendor && hugo mod vendor

// Lint a vendor/modules.txt before Hugo parses it
import ("bufio"; "os"; "strings")

func lintModulesTxt(path string) error {
  f, err := os.Open(path)
  if err != nil { return err }
  defer f.Close()
  s := bufio.NewScanner(f)
  for s.Scan() {
    line := strings.TrimSpace(strings.TrimPrefix(strings.TrimSpace(s.Text()), "# "))
    if line == "" { continue }
    if len(strings.Fields(line)) != 2 { return fmt.Errorf("bad line: %q", line) }
  }
  return s.Err()
}

null

// On 'invalid modules list:', regenerate vendor/ rather than patching by hand.

When it happens

Trigger: A _vendor/modules.txt containing a comment line that wasn't stripped, a wrapped/truncated line, a hand-merged file with stray text, or a vendor dir produced by a tool that diverges from go's format.

Common situations: Manually editing modules.txt to add/remove a vendored dep, a bad merge conflict resolution leaving a 3-field or 1-field line, or a pre-Go-1.14 vendor format.

Related errors

• failed to apply mounts for project
• module not found in ; either add it as a Hugo Module or…
• : : mount source must be a local path for modules/themes
• cannot vendor module
• could not determine content directory for

AI-assisted analysis of gohugoio/hugo@52c9bd7908 (2026-08-09). Data as JSON: /api/errors/33cfe671439302da. Report an issue: GitHub.

Appendix: source

Thrown at modules/collect.go:625

		return err
	}

	defer f.Close()

	scanner := bufio.NewScanner(f)

	for scanner.Scan() {
		// # github.com/alecthomas/chroma v0.6.3
		line := scanner.Text()
		line = strings.Trim(line, "# ")
		line = strings.TrimSpace(line)
		if line == "" {
			continue
		}
		parts := strings.Fields(line)
		if len(parts) != 2 {
			return fmt.Errorf("invalid modules list: %q", filename)
		}
		path := parts[0]

		shouldAdd := c.Client.moduleConfig.VendorClosest

		if !shouldAdd {
			if _, found := c.vendored[path]; !found {
				shouldAdd = true
			}
		}

		if shouldAdd {
			c.vendored[path] = vendoredModule{
				Owner:   owner,
				Dir:     filepath.Join(vendorDir, path),
				Version: parts[1],
			}
		}

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