prerm is in guile-2.2-doc 2.2.3+1-3build1.
This file is a maintainer script. It is executed when installing (*inst) or removing (*rm) the package.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 | #! /bin/sh
set -e
if [ "$1" != "upgrade" ] ; then
update-alternatives --remove guile.info.gz \
/usr/share/info/guile-2.2/guile.info.gz
fi
|