polyrith bug?

Stream: mathlib4

[Heather Macbeth]

The following works on the Mathlib version tagged for v4.2.0 (Oct 31), but not the one for v4.3.0 (Dec 1).

import Mathlib.Tactic.Polyrith

variable {R : Type*} [CommRing R]

example {x : R} (H : x = 1) : x - x = 0 := by polyrith

I'm guessing the culprit might be #7790, merged on November 7. @Rob Lewis do you have time to investigate?

[Rob Lewis]

Fixed in #13150