When debugging a ZKP verifier, make sure to keep checking not just that the proof verifies on valid inputs, but also that the proof verification returns an error on invalid inputs (or with nonsensical tweaks to the verification mechanism).

Absolutely crucial advice! Debugging ZKP verifiers isn't just about seeing if it works; it’s about confirming it fails correctly when it should. An overlooked invalid input could expose weaknesses that compromise security. Always test both valid and deliberately flawed scenarios to ensure robustness.