Signature over symptom

When a bug is platform-specific and you're on a different platform, the tempting move is "cannot reproduce, needs <that OS/hardware>." That's often a framing error. The symptom may need the hardware; the cause usually doesn't.

A platform-specific symptom is almost always produced by a platform-independent mechanism: a leaked file descriptor, a wrong/missing spawn flag, a window surface that paints wrong, a binary missing from an artifact, a keychain item from a bundle id. Each leaves a structural signature observable on the machine you already have. The bug crashes on Windows, but why it crashes is visible on your Mac. Done well this beats reproducing the symptom: you hand a maintainer the exact fd or missing flag, more actionable than "repros for me too."

Certainty levels — label every finding as one (read first)

A signature is a HYPOTHESIS, not proof. Never say "root cause confirmed" unless you closed the loop.