=> Bootstrap dependency digest>=20010302: found digest-20080510
===> Skipping vulnerability checks.
WARNING: No /var/db/pkg/pkg-vulnerabilities file found.
WARNING: To fix run: `/usr/sbin/pkg_admin -K /var/db/pkg fetch-pkg-vulnerabilities'.
===> Installing for swi-prolog-packages-5.6.17nb2
Error: Environment variable DISPLAY must be set
       and point to a connectible X server.
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/lang/swi-prolog-packages
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/lang/swi-prolog-packages
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc/lang/swi-prolog-packages