odd message from ld in -current around 9.0 branchpoint

I'm trying to compile a system based on current from just before the 
9.x branchpoint.

during hte build I got the following message:

       /usr/bin/ld: this linker was not configured to use sysroots

does anyone have any idea what this means in a broader context?
did I misconfigure something when I built this system?

Julian