postinst is in chimera2 2.0a19-8.
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  | #!/bin/sh
set -e 
# Register in menu
if [ "$1" = "configure" ] && [ -x "$(which update-menus 2>/dev/null)" ]; then
    update-menus
fi
# Install alternatives
update-alternatives --install \
    /usr/bin/x-www-browser x-www-browser /usr/bin/chimera2 30 \
    --slave /usr/share/man/man1/x-www-browser.1.gz x-www-browser.1.gz \
    /usr/share/man/man1/chimera2.1.gz
 |