prerm is in guile-2.0 2.0.13+1-5build2.
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 \
/usr/lib/x86_64-linux-gnu/guile-2.0/bin/guile
fi
|