docker/compose · error · ErrParsingFailed

parsing failed

Error message

parsing failed

What it means

api.ErrParsingFailed is the sentinel for string-to-object parse failures inside the api layer (for example failing to parse a filter value, an ID, or a serialized payload into its structured form). It exists so callers can distinguish malformed input from engine/transport errors.

Source

Thrown at pkg/api/errors.go:45

)

var (
	// ErrNotFound is returned when an object is not found
	ErrNotFound = errors.New("not found")
	// ErrAlreadyExists is returned when an object already exists
	ErrAlreadyExists = errors.New("already exists")
	// ErrForbidden is returned when an operation is not permitted
	ErrForbidden = errors.New("forbidden")
	// ErrUnknown is returned when the error type is unmapped
	ErrUnknown = errors.New("unknown")
	// ErrNotImplemented is returned when a backend doesn't implement an action
	ErrNotImplemented = errors.New("not implemented")
	// ErrUnsupportedFlag is returned when a backend doesn't support a flag
	ErrUnsupportedFlag = errors.New("unsupported flag")
	// ErrCanceled is returned when the command was canceled by user
	ErrCanceled = errors.New("canceled")
	// ErrParsingFailed is returned when a string cannot be parsed
	ErrParsingFailed = errors.New("parsing failed")
	// ErrNoResources is returned when operation didn't selected any resource
	ErrNoResources = errors.New("no resources")
)

// IsNotFoundError returns true if the unwrapped error is ErrNotFound
func IsNotFoundError(err error) bool {
	return errors.Is(err, ErrNotFound)
}

// IsAlreadyExistsError returns true if the unwrapped error is ErrAlreadyExists
func IsAlreadyExistsError(err error) bool {
	return errors.Is(err, ErrAlreadyExists)
}

// IsForbiddenError returns true if the unwrapped error is ErrForbidden
func IsForbiddenError(err error) bool {
	return errors.Is(err, ErrForbidden)
}

View on GitHub (pinned to ddc4b044b6)

Solutions

1. Correct the input string to the documented format for the option being parsed.
2. Validate values in your script before passing them (regex or dry-run with docker compose config).
3. On version-skew suspicions, align composer/engine versions and retry.

# dry-run parse check before the real command
docker compose config --quiet || { echo "compose file/inputs failed to parse" >&2; exit 1; }

func isParsingFailed(err error) bool { return errors.Is(err, api.ErrParsingFailed) }

if err := parseInput(s); err != nil {
    if errors.Is(err, api.ErrParsingFailed) {
        return fmt.Errorf("invalid input %q: %w", s, err)
    }
    return err
}

When it happens

Trigger: Passing a malformed string to an api helper that must parse it (e.g. an invalid filter or argument format reaching a parsing function); backends wrapping decode errors into this sentinel.

Common situations: Hand-written filter strings with bad syntax; payloads produced by a different compose version being parsed by an older one; scripts feeding unescaped values into parse-based options.

Related errors

• not found
• already exists
• forbidden
• unknown
• not implemented

AI-assisted analysis of docker/compose@ddc4b044b6 (2026-08-15). Data as JSON: /api/errors/70617cba0291bf30. Report an issue: GitHub.