pub fn maybe_fail_at(name: &str) -> Result<()>Expand description
Like maybe_panic_at, but returns an io::Error instead of
panicking — for exercising in-process error-recovery paths (a
graceful failure that drives a rollback) rather than crash recovery.
Production callers thread this where a returned error must unwind a
partially-applied operation; tests opt in by listing the checkpoint
name in HEDDLE_FAULT_INJECT and assert the rollback left no
partial state. With the env var unset the cached None
short-circuits, exactly like maybe_panic_at.