lima-vm/lima · error

identifier %#q greater than maximum length (%d characters)

Error message

identifier %#q greater than maximum length (%d characters)

What it means

Validate checks that an identifier (instance name, disk name, etc.) is non-empty, within the maximum length, and matches the allowed character pattern. This error is returned when the string exceeds maxLength characters. Lima enforces a uniform identifier limit so names remain safe for use as file names, DNS-ish labels, and command arguments.

Source

Thrown at pkg/identifiers/validate.go:63

)

// identifierRe defines the pattern for valid identifiers.
var identifierRe = regexp.MustCompile(reAnchor(alphanum + reGroup(separators+reGroup(alphanum)) + "*"))

// Validate returns nil if the string s is a valid identifier.
//
// Identifiers are similar to the domain name rules according to RFC 1035, section 2.3.1. However
// rules in this package are relaxed to allow numerals to follow period (".") and mixed case is
// allowed.
//
// In general identifiers that pass this validation should be safe for use as filesystem path components.
func Validate(s string) error {
	if s == "" {
		return errors.New("identifier must not be empty")
	}

	if len(s) > maxLength {
		return fmt.Errorf("identifier %#q greater than maximum length (%d characters)", s, maxLength)
	}

	if !identifierRe.MatchString(s) {
		return fmt.Errorf("identifier %#q must match %v", s, identifierRe)
	}
	return nil
}

func reGroup(s string) string {
	return `(?:` + s + `)`
}

func reAnchor(s string) string {
	return `^` + s + `$`
}

View on GitHub (pinned to dd909d0973)

Solutions

1. Shorten the identifier to at most maxLength characters (see pkg/identifiers/validate.go for the constant; historically 128)
2. Use `limactl create` with a shorter explicit --name instead of a derived path
3. If the name is generated, truncate or hash the long portion before passing it to Lima

Example fix

// before
name := "ci-" + longBranchSlug // >128 chars
err := identifiers.ValidateInstName(name)
// after
if len(longBranchSlug) > 100 { longBranchSlug = longBranchSlug[:100] }
name := "ci-" + longBranchSlug
err := identifiers.ValidateInstName(name)

func validIdentLen(s string) bool { return len(s) > 0 && len(s) <= 128 } // check before identifiers.Validate
if !validIdentLen(name) { name = name[:128] }

func isShortEnough(s string, max int) bool { return len(s) <= max }

When it happens

Trigger: Calling identifiers.Validate (directly or via ValidateInstName, InstNameFromYAMLPath, ValidateTemplateArgs, or DiskDir) with a string longer than maxLength, e.g. an instance name built from a long YAML path or a template arg like `limactl create --name=<very-long-name>`.

Common situations: Users deriving instance names from long file paths or hostnames; CI systems generating machine names from long branch/PR slugs; copying long UUIDs or template URLs as names.

Related errors

• invalid value for number of cpus, must be >= 0
• identifier %#q must match %v
• field `provision[%d].mode` cannot set skipDefaultDependencyR
• field `provision[%d].path` must not be empty when mode is %#
• field `provision[%d].path` must be an absolute path

AI-assisted analysis of lima-vm/lima@dd909d0973 (2026-09-01). Data as JSON: /api/errors/f5d96ebb39f642c3. Report an issue: GitHub.