docker/cli · error

invalid field '%s' must be a key=value pair

Error message

invalid field '%s' must be a key=value pair

What it means

Error "invalid field '%s' must be a key=value pair" thrown in docker/cli.

Source

Thrown at opts/mount.go:63

		if hasValue {
			v := strings.TrimSpace(val)
			if v == "" {
				return fmt.Errorf("invalid value for '%s': value is empty", key)
			}
			if v != val {
				return fmt.Errorf("invalid value for '%s' in '%s': value should not have whitespace", key, field)
			}
		}

		// TODO(thaJeztah): these options should not be case-insensitive.
		key = strings.ToLower(key)

		if !hasValue {
			switch key {
			case "readonly", "ro", "volume-nocopy", "bind-nonrecursive", "bind-create-src":
				// boolean values
			default:
				return fmt.Errorf("invalid field '%s' must be a key=value pair", field)
			}
		}

		switch key {
		case "type":
			mount.Type = mounttypes.Type(strings.ToLower(val))
		case "source", "src":
			mount.Source = val
			if !filepath.IsAbs(val) && strings.HasPrefix(val, ".") {
				if abs, err := filepath.Abs(val); err == nil {
					mount.Source = abs
				}
			}
		case "target", "dst", "destination":
			mount.Target = val
		case "readonly", "ro":
			mount.ReadOnly, err = parseBoolValue(key, val, hasValue)
			if err != nil {

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at opts/mount.go:63 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of docker/cli@e9452d6e78 (2026-08-01). Data as JSON: /data/errors/d28a304f6c9219cc.json. Report an issue: GitHub.