Actually it's 7 [1]
But in my future backend revamp I plan to make the default 6 [2]
Note that the line can easily be updated to
const MAXRANK* {.intdefine.} = 6
nim c -d:MAXRANK=16 path/to/my/app
[2]: https://github.com/numforge/laser/blob/d1e6ae6106564bfb350d4...