lock port for concurrent builds
lockname [comment ...]
creates a lock named
If the lock is already held, it will display one single wait message on
stderr, sleep and retry until satisfaction.
If necessary, creates the lock directory, using
-m mode as a mode argument or
the default if that option is not specified, and
group as the group owner if that option is
This implements a locking mechanism for ports building, see
‘LOCK INFRASTRUCTURE’ in
ports(7) for details. See also
dpb(1) for a complementary lock
infrastructure when using dpb.