# RP20 — Part C: an unwritable block keeps the gate closed
# mutation in internal/stacks/setup_gate.go:
#   - '\t\t\treturn fmt.Errorf("setup gate %s: the sign-up block could not be written, so the gate stays closed: %w", name, err)'
#   + '\t\t\t_ = err // RED-PROOF RP20'
# go test -run ^TestSignupBlock_UnwritableBlockKeepsTheGateClosed$ ./internal/stacks
# verdict: RED (assertion)
=== RUN   TestSignupBlock_UnwritableBlockKeepsTheGateClosed
    signup_block_test.go:52: the gate opened although the sign-up block could not be written
--- FAIL: TestSignupBlock_UnwritableBlockKeepsTheGateClosed (0.00s)
