The command line I am using is
dpkg --force-not-root --root /some/other/location -i the_package.deb
but I get an error
dpkg: could not open log '/var/log/dpkg.log': Permission denied
I would have expected the log to have been written to
/some/other/location/var/log/dpkg.log
With rpm you can generate an alternate database but I can't see how to do this with dpkg. To get to the above state I manually added (perhaps not the wisest approach) the following.
mkdir -p /some/other/location/var/lib/dpkg/updates
mkdir -p /some/other/location/var/lib/dpkg/triggers
mkdir -p /some/other/location/var/lib/dpkg/info
touch /some/other/location/var/lib/dpkg/status
touch /some/other/location/var/lib/dpkg/available
If I try to run as root, which I would prefer not to do in this case
sudo dpkg --force-not-root --root /some/other/location -i the_package.deb
it gets further and installs the deb in my alternate location but then fails with
dpkg (subprocess): unable to execute installed post-installation script (/var/lib/dpkg/info/the_package.postinst): No such file or directory
but this file has been written by the dpkg command above to
/some/other/location/var/lib/dpkg/info/the_package.postinst
My reasoning for not using the machines dpkg database is that this is an applications software install to a network drive that is available to a number of users. Perhaps just extracting the contents of the package and manually installing is the best approach. The particular software package does not have any external dependencies listed.
Debian 'dpkg' package management program version 1.18.2 (amd64)