make buildworld fails in 11.0-RELEASE

[Christoph P.U. Kukulies]

I did a make buildworld in 11.0-RELEASE (which I updated to by 
freebsd-update), then downloaded the sources
via  fetch 
ftp://ftp.freebsd.org/pub/FreeBSD/releases/amd64/11.0-RELEASE/src.txz

make buildworld fails:


===> usr.sbin/pc-sysinstall (cleandir)
===> usr.sbin/pc-sysinstall/backend (cleandir)
rm -f .depend .depend.*
===> usr.sbin/pc-sysinstall/backend-partmanager (cleandir)
rm -f .depend .depend.*
===> usr.sbin/pc-sysinstall/backend-query (cleandir)
rm -f .depend .depend.*
===> usr.sbin/pc-sysinstall/conf (cleandir)
rm -f .depend .depend.*
===> usr.sbin/pc-sysinstall/doc (cleandir)
rm -f .depend .depend.*
===> usr.sbin/pc-sysinstall/examples (cleandir)
rm -f .depend .depend.*
===> usr.sbin/pc-sysinstall/pc-sysinstall (cleandir)
rm -f pc-sysinstall.8.gz pc-sysinstall.8.cat.gz
rm -f .depend .depend.*
===> usr.sbin/ftp-proxy (cleandir)
rm -f ftp-proxy ftp-proxy.full ftp-proxy.debug ftp-proxy.o filter.o 
ftp-proxy.8.gz ftp-proxy.8.cat.gz
rm: ftp-proxy: is a directory
*** Error code 1

Stop.
make[4]: stopped in /usr/src/usr.sbin/ftp-proxy
*** Error code 1

Stop.
make[3]: stopped in /usr/src/usr.sbin
*** Error code 1

Stop.
make[2]: stopped in /usr/src
*** Error code 1

Stop.
make[1]: stopped in /usr/src
*** Error code 1

Stop.
make: stopped in /usr/src


--

Christoph