Syntax to reference tasks from top level

[postlund]

I have a bunch of tasks that I re-use from other tasks within my repo that I have put inside a directory simply called buildsystem in the repo root. It is however very inconvenient to have to use :, ::, :::, etc. depending on where in the include-hierarchy I am. A syntax to reference the root would be very convenient, e.g. @buildsystem:my_task.