So it appears to fail only on Safari in the iPhone simulator
, at least with my current test now at https://output.jsbin.com/tayoje
. If run in iPhone sim's Safari I see a failure rate of 6.1% over 2000 tries. Same code run on Windows Firefox or Chrome, MacOS Safari, actual iPhone Safari, Android Chrome, or BB10 browser does not
show the failure. I can post as a bug report with a traceback if you want. Since it appears unlikely that it will happen in production I don't need to explore further but am happy to try out suggested experiments. Might also be nice just to have confirmation that someone else can reproduce the failure in the iPhone simulator. It could be a flaw in the iPhone sim or its version of Safari and nothing to do with CanJS, but could represent a latent flaw in CanJS itself.