New creates a new error with stacktrace.

NewSentinel error, without a stacktrace or metadata assigned to it.

NewWithType creates a new error with stacktrace and a custom type string returned by its Type() method.

SentinelWithStack wraps the given sentinel error.

W wraps an error in a new error with stacktrace and propagating the metadata.

Wrap wraps the given error in a new Error with the given message, having a stacktrace and propagating metadata.

Wrap a sentinel error as another sentinel error, without a stacktrace or metadata assigned to it.

Wrap wraps the given error in a new error with stack trace and a custom type string returned by its Type() method.

As finds the first error in err's tree that matches target, and if one is found, sets target to that error value and returns true.

Is reports whether any error in err's tree matches target.