Death by vmmap
https://objective-see.com/blog/blog_0x3E.html [objective-see.com]
2019-03-20 14:42
In this blog post, we dug into why (on macOS Mojave) executing vmmap against launchd (pid 1), deadlocks the entire system. In short, after vmmap has suspended launchd it (indirectly) attempts to ‘call’ into launchd via XPC. As launchd has been suspended (by vmmap), everything grinds to a halt.
source: L