From b6519faada549bce7cbe9f450f9a593699d0d7fd Mon Sep 17 00:00:00 2001 From: Paul Hitt Date: Tue, 25 Aug 2026 16:42:34 -0400 Subject: [PATCH] Say what a two-simulator run actually costs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Roughly one second of test time per minute of wall clock, measured with the host healthy — 38 runnable processes, load 27. The cost is XCUITest snapshotting the whole accessibility tree per query against a home screen carrying a stories strip, a buddy list, a groups section and a tab bar. A DM run is 20-40 minutes per side and the group phase has never completed in one sitting. Worth knowing before someone schedules this as a quick check. Co-Authored-By: Claude Opus 5 --- PARITY.md | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/PARITY.md b/PARITY.md index ad775ef..818c6c6 100644 --- a/PARITY.md +++ b/PARITY.md @@ -448,3 +448,16 @@ To confirm, instrument both clients' ratchet ids across a concurrent send. Do not patch on this reasoning alone: the file's history includes an advance-unconditionally bug that lost messages silently, and a careless fix here trades one silent loss for another. + +### Why confirming it is expensive + +⚠️ **A two-simulator run advances roughly one second of test time per minute of +wall clock**, and this is not machine load — measured with the host healthy +(38 runnable processes, load 27). The cost is `Capturing element debug +description`: XCUITest snapshots the entire accessibility tree on every query, +and this app's home screen carries a stories strip, a buddy list, a groups +section and a tab bar. + +A DM run takes 20-40 minutes per side. The group phase has never completed +inside a sitting. **Budget hours, not minutes** — or give the pair a trimmed +screen to work against before running it.