This package contains four tools to ease creating and maintaining
patches for pkgsrc: mkpatches, patchdiff, pkgdiff, and pkgvi.

pkgdiff compares two files (like diff) and produces an output file
that can be used in pkgsrc.

mkpatches automatically generates a set of patches, if the original
versions of the files had been saved as filename.orig.

patchdiff compares a previously existing set of patches with another
one created by mkpatches, and outputs any changes.

pkgvi makes backup copies if a file is changed, so pkgdiff can be run
on it later, generating a patch for the changes made.

Homepage:
https://cdn.NetBSD.org/pub/pkgsrc/current/pkgsrc/doc/pkgsrc.html
