Fail do build on amd64: nbmtree: .: missing directory in specification

[Riccardo Mottola <riccardo.mottola%libero.it@localhost>]

Hi,

just tried to update since a loong time. I updated source, built the 
kernel, tools just fine.

However distribution fails with the error below. Ideas?

Riccardo

obj ===> regress/sys/kern/ras/ras3
obj ===> regress/sys/kern/unfdpass
clean_METALOG ===> .
clean_METALOG ===> distrib/sets
</usr/src/obj/destdir.amd64/METALOG 
/usr/src/obj/tooldir.NetBSD-9.99.79-amd64/bin/nbawk '{ a[$1] = $0; } END 
{ for (f in a) print a[f]; }' |   sort | 
/usr/src/obj/tooldir.NetBSD-9.99.79-amd64/bin/nbmtree -CSM -k all -R 
time -N /usr/src/etc  >/usr/src/obj/destdir.amd64/METALOG.new
nbmtree: .: missing directory in specification
nbmtree: failed at line 1 of the specification

*** Failed target:  /usr/src/obj/destdir.amd64/METALOG.sanitised
*** Failed command: </usr/src/obj/destdir.amd64/METALOG 
/usr/src/obj/tooldir.NetBSD-9.99.79-amd64/bin/nbawk '{ a[$1] = $0; } END 
{ for (f in a) print a[f]; }' | sort | 
/usr/src/obj/tooldir.NetBSD-9.99.79-amd64/bin/nbmtree -CSM -k all -R 
time -N /usr/src/etc >/usr/src/obj/destdir.amd64/METALOG.new
*** Error code 1