Code:
# cd /usr/ports/lang/ruby18
# make all-depends-list
/usr/ports/security/openssl
/usr/ports/devel/automake
/usr/ports/devel/autoconf
/usr/ports/lang/perl5.12
/usr/ports/devel/makedepend
/usr/ports/devel/automake-wrapper
/usr/ports/devel/m4
/usr/ports/misc/help2man
/usr/ports/devel/gmake
/usr/ports/devel/autoconf-wrapper
/usr/ports/x11/xproto
/usr/ports/devel/pkg-config
/usr/ports/devel/p5-Locale-gettext
/usr/ports/devel/gettext
/usr/ports/devel/libtool
/usr/ports/converters/libiconv
If all dependencies are installed, EXCEPT:
/usr/ports/devel/automake
/usr/ports/devel/autoconf
# make missing
won't list:
/usr/ports/devel/automake
/usr/ports/devel/autoconf