postrm is in geda-symbols 1:1.8.2-5.
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 9 10 11 12 13 14 15 | #!/bin/sh
set -e
OLDCONF=/etc/gEDA/system-gafrc
if [ "$1" = purge ]; then
	# geda-symbols used to own /etc/gEDA/system-gafrc, but now it
	# belongs to libgeda-common. If that package is installed and
	# owns the config file, don't remove it here.
	if [ -f /var/lib/dpkg/info/libgeda-common.conffiles ]; then
		if ! grep -q $OLDCONF /var/lib/dpkg/info/libgeda-common.conffiles ; then
			echo Removing old configuration file $OLDCONF ...
			rm -f $OLDCONF || true
		fi
	fi
fi
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