The *_FOREACH macros got added post 1.5 and were pulled up into 1.5.2. This
makes it impossible to compile mtree local on a 1.5-release box as a cross
toolchain bit for bootstrapping to -current. (and why I never saw this problem
on my 1.5.2 machine)
This whole thing is solved via a compat lib for the tools for all netbsd bits
and/or trimming down a version of mtree to just the bits needed for building
the snapshots.