In addition to 4768 there's https://github.com/sylabs/singularity/issues/4755 which breaks OSG regression tests. There are all these fixes queued already for 3.5.1 https://github.com/sylabs/singularity/milestone/43?closed=1 and sylabs has particularly called out https://github.com/sylabs/singularity/pull/4754 as a bad one that is pushing them for a quick 3.5.1 release.
I wanted to push to stable today, but the only button available was "Unpush" so I tried that. That was the wrong thing to do; later I realized the reason why I couldn't push to stable was because of last week's accidental too early push reset the clock for 14 days. Now this will have to wait another 14 days.