tscircuit-autorouter (tscircuit)ECADConfidence: Medium
Bus length matching measures only newly routed copper, so it can report skew success while retained fanout copper breaks it, repro A at 19 mm against B at 10 mm against a 0.1 mm limit with zero DRC errors.
From the Grok pain-radar digests, Oct 26-27 2026 (Oct 26 12:41 PM ET through Oct 27 7:41 AM ET digests plus the Haitch editions). Verified live 2026-10-27: issue/PR/thread read; title and state confirmed.