While building vlc, I saw the following:
pkg_info: missing package name(s)
usage: pkg_info [-BbcDdFfhIikLmNnpqRSsVvX] [-e package] [-E package]
[-K pkg_dbdir] [-l prefix] pkg-name ...
pkg_info [-a | -u] [flags]
pkg_info [-Q variable] pkg-name ..
--Steve Bellovin, http://www.cs.columbia.edu/~smb