There is a lot of confusion around mach try. People frequently ask “How do I get task X in mach try fuzzy?” or “How can I avoid getting backed out?”. This post is not so much a tip, rather an explanation around how mach try works and its relationship to the CI system (taskgraph). Armed with this knowledge, I hope you’ll be able to use mach try a little more effectively.

https://ahal.ca/blog/2021/understanding-mach-try/