What's up with shlock and Darwin?

cd /usr/pkgsrc/pkgtools/pkglint && /usr/pkg/bin/bmake update CLEANDEPENDS=yes
===> Checking for vulnerabilities in pkglint-4.16
The "/usr/pkg/bin/shlock" utility does not exist, and is necessary for locking.
Please "/usr/pkg/bin/bmake install" in ../../pkgtools/shlock.
*** Error code 1

Stop.
bmake: stopped in /usr/pkgsrc/pkgtools/pkglint

...

$ cd /opt/pkgsrc/pkgtools/shlock
$ make
===> shlock-20020114 is not available for Darwin-7.9.0-powerpc