app-editors/nvi is based on very old code needing a lot of patches, and
can be well replaced by >=app-edtors/vim-8.1.1155[minimal].
no patches and updates since 2010?
Seems to be really dead.
I think you should really last rite it.
see "Removing a package"
Please ask on IRC, if you need help.
It is not that dead, a few patches have been accepted since 2010:
The last time I heard anything from the maintainer was in January 2017.