Hi.

I know I can get a list of the packages installed on a currently-running
system using commands such as:

    dpkg-query -l
    apt list --installed
    aptitude search ~i

However, if there any way I can do the same thing, but when I simply have a
copy (backup) of the machine, and it's not currently running? The backup is
on another Debian / Devuan system (which may or may not be the same release
version).

I have _all_ files from the machine I want to investigate, and I'm hoping that
there's something in /var/cache/apt or /var/lib/dpkg which would allow me to
get the same sort of list as the above commands produce.

Does anyone have any ideas?


Antony.

--
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