as PREFER_PKGSRC. Preferences are determined by the most specific
instance of the package in either PREFER_PKGSRC or PREFER_NATIVE. If
a package is specified in neither or in both variables, then PREFER_PKGSRC
has precedence over PREFER_NATIVE.
BUILDLINK_PREFER_PKGSRC
This variable determines whether or not to prefer the pkgsrc
versions of software that is also present in the base system.
This variable is multi-state:
defined, or "yes" always prefer the pkgsrc versions
not defined, or "no" only use the pkgsrc versions if
needed by dependency requirements
This can also take a list of packages for which to prefer the
pkgsrc-installed software. The package names may be found by
consulting the value added to BUILDLINK_PACKAGES in the
buildlink[23].mk files for that package.