Make sure the port honors WRKDIRPREFIX. Most ports do not have to worry about this. In particular, when referring to a WRKDIR of another port, note that the correct location is WRKDIRPREFIXPORTSDIR/subdir/name/work not PORTSDIR/subdir/name/work or .CURDIR/../../subdir/name/work or some such.

Also, if defining WRKDIR, make sure to prepend ${WRKDIRPREFIX}${.CURDIR} in the front.