pkg_delete: package 'xorg-drivers-7.3' doesn't have a prefix

[Stephen Montgomery-Smith]

Mon Si wrote:
> Dear list,
> 
> I'm experiencing problems when I try to portupgrade the xorg-driver
> port. The old version of the port can't be uninstalled during the
> portupgrade due to an undefined prefix.
> The port can't be deleted by "pkg_delete -f xorg-drivers-7.3"
> 
> Does anybody know how to upgrade / remove this port?
> 
> Thanks in advance,
> 	Simon

If nothing else works, you could try
rm -rf /var/db/pkg/xorg-drivers-7.3