[stable/11] error during installworld: missing directory /usr/tests/sys/netgraph/

Dear All,

I tried to `make installworld' from recent 11-STABLE sources and it
stopped a "tests/sys/netgraph (install)"

Apparently, directory /usr/tests/sys/netgraph/ was not created, but we
are trying to install(1) a file in there anyway.

The sources are from last Friday. I updated them now from git but
there do no seem to be any relevant changes.

The commands I issued where:

 # make buildworld
 # make kernel
 # make installworld    <--- failed

Error log:

----8<--------8<--------8<--------8<--------8<--------8<--------8<---------

===> tests/sys/netgraph (install)
install  -o root  -g wheel -m 444  Kyuafile  /usr/tests/sys/netgraph/Kyuafile
install: /usr/tests/sys/netgraph/Kyuafile: No such file or directory
*** Error code 71

Stop.
make[6]: stopped in /usr/src/tests/sys/netgraph

*** Error code 1

----8<--------8<--------8<--------8<--------8<--------8<--------8<---------

If anyone requires any more information, just let me know.

Best regards,
-- 
Arrigo