post_upgrade() {
    if (( $(vercmp '2.0.0-1' "$2") == 1 )); then
        cat >&2 <<-EOF
As of 2.0.0, aurutils no longer supports repose. If you have repose installed,
please rebuild your local repository using repo-add. See:

https://bbs.archlinux.org/viewtopic.php?pid=1707649#p1707649

for detailed instructions. For the 2.0.0 changelog, see:

https://github.com/AladW/aurutils/releases/tag/2.0.0

EOF
    fi

    if (( $(vercmp '3.0.0-1' "$2") == 1 )); then
        cat >&2 <<-EOF
As of 3.0.0, aurutils requires a separate pacman configuration for chroot
builds.  The file path defaults to /usr/share/devtools/pacman/aur.conf.

For this and other changes, see the aurutils 3.0 blog:

https://pkgbuild.com/~alad/aurutils_3.html

EOF
    fi

    if (( $(vercmp '3.1.0-1' "$2") == 1 )); then
        cat >&2 <<-EOF
As of 3.1.0, the default path of the pacman configuration for chroot builds
moved from /usr/share/devtools/pacman-aur.conf to

/etc/aurutils/pacman-<repository name>.conf

More information about this file was added to the aur-build man page.
EOF
    fi
}