After your register your depot:
# swreg -l depot /dir/to/my/depot
And you try to install install you get the error in /var/adm/sw/swinstall.log or as std out:
ERROR: "my_host:/dir/to/my/depot": Cannot establish a lock on this target because of an external error (for example, the lock file could not be created).
# cd /dir/to/my/depot/catalog # touch swlock # chmod 666 swlock # swagentd -r
Now swinstall should work.