Problem updatin ports

[Filippo Moretti]

root  sting /usr/ports 12:06:42$ portmaster 'find /usr/local/lib/perl5/site_perl/mach/5.18 -name '*.so' |xargs pkg which -qolsort -u'

===>>> find is not installed
===>>> Aborting update

root  sting /usr/ports 12:10:11$ uname -a
FreeBSD sting 10.1-STABLE FreeBSD 10.1-STABLE #8 r275607: Fri Dec 12 12:52:06 CET 2014     root at sting:/usr/obj/usr/src/sys/STING_VT  i386

I get this error when attempting to update ports and I do have /usr/bin/find installedany help appreciatedFilippo