Usage outputs a usage error and exits with error code 64.

WithCode outputs a fatal error message and exits with a supplied error code.

WithError outputs an error and exits.

WithProblems outputs an error along with any autodetected problems, and exits.

Usage represents an incorrect command line.

Config represents an unconfigured or miscon­figured state.

Data represents incorrect data supplied by the user.

Failure represents a general failure code.

IO represents an I/O error.

MaxProblems controls the number of problems to show for each source.

NoInput represents that the input file did not exist or was not readable.

Permissions represents a permissions error.

Software represents an internal software error.

Unavailable represents when a service was unavailable.