dgraph-io/dgraph · error

error parsing flag `%s`: %w

Error message

error parsing flag `%s`: %w

What it means

formatAsFlagParsingError wraps a parseVersionFromString failure with the flag name that had the bad value. It is produced when the --from or --to value passed to dgraph upgrade cannot be parsed as a vMAJOR.MINOR.PATCH version string.

Source

Thrown at upgrade/upgrade.go:203

	fromVersionParsed, err := parseVersionFromString(Upgrade.Conf.GetString(from))
	if err != nil {
		return nil, formatAsFlagParsingError(from, err)
	}

	toVersionParsed, err := parseVersionFromString(Upgrade.Conf.GetString(to))
	if err != nil {
		return nil, formatAsFlagParsingError(to, err)
	}

	if fromVersionParsed.Compare(toVersionParsed) != less {
		return nil, fmt.Errorf("error: `%s` must be less than `%s`", from, to)
	}

	return &commandInput{fromVersion: fromVersionParsed, toVersion: toVersionParsed}, nil
}

func formatAsFlagParsingError(flag string, err error) error {
	return fmt.Errorf("error parsing flag `%s`: %w", flag, err)
}

// parseVersionFromString parses a version given as string to internal representation.
// Some examples for input and output:
//  1. input : v1.2.2
//     output: &version{major: 1, minor: 2, patch: 2}, nil
//  2. input : v20.03.0-beta.20200320
//     output: &version{major: 20, minor: 3, patch: 0}, nil
//  3. input : 1.2.2
//     output: nil, error
//  4. input : v1.2.2s
//     output: nil, error
func parseVersionFromString(v string) (*version, error) {
	v = strings.TrimSpace(v)
	if v == "" || v[:1] != "v" {
		return nil, fmt.Errorf("version can't be empty and must start with `v`. E.g.: v1.2.2")
	}

View on GitHub (pinned to 759e242be6)

Solutions

1. Pass an exact semver string with a leading v, e.g. -f v21.03.2 -t v21.03.3.
2. Check the wrapped error after 'error parsing flag' to see the specific parse failure and correct that component.
3. Trim whitespace/quotes in scripts before passing the version.
4. Run dgraph version to confirm your current version string format.

Example fix

// before
dgraph upgrade offline -f 21.03.0 -t v21.03.2
// after
dgraph upgrade offline -f v21.03.0 -t v21.03.2

var semverRe = regexp.MustCompile(`^v\d+\.\d+\.\d+$`)
func isValidVersionFlag(s string) bool { return semverRe.MatchString(strings.TrimSpace(s)) }
// use: if !isValidVersionFlag(fromVer) || !isValidVersionFlag(toVer) { correct values first }

When it happens

Trigger: Running dgraph upgrade with a malformed --from or --to value such as 21.03 (no v prefix), v21.03 (missing patch), or v21.03.0.0 (extra component).

Common situations: Omitting the leading v, using image tags like latest or main as versions, shell scripts interpolating untrimmed/unset variables.

Related errors

• error: `%s` must be less than `%s`
• version can't be empty and must start with `v`. E.g.: v1.2.2
• error parsing major version: %w
• Key size value is too large (x > 4096)
• Key size value must be a factor of 2

AI-assisted analysis of dgraph-io/dgraph@759e242be6 (2026-09-01). Data as JSON: /api/errors/6972bd41aceb8827. Report an issue: GitHub.