Carp(3p) on OpenBSD
The text 271eb0edb7ac, as OpenBSD 5.3, OpenBSD 5.2, OpenBSD 5.1, OpenBSD 5.0 shipped it.
warn of errors (from perspective of caller) cluck - warn of errors with stack backtrace (not exported by default) croak - die of errors (from perspective of caller) confess - die of errors with stack backtrace