FYI, adding the packages without JetPack is not supported…but you can still do it if you are willing to go through some manual steps.
Just to note, on a Jetson TX2 with R28.2 and several packages installed, you’ll find several local repositories. Normally “apt-get” looks to repositories over the internet…it is possible to have a local file-based repository, and this is what the “repo” packages add. Once the “repo” package is added you can freely add any package within it. This R28.2 TX2 has:
Within these are all of the available “.deb” packages, along with the typical repo files about versioning and checksums.
Within a JetPack’s installation (at least after it is used once) there will be file “repository.json”. This contains XML-based descriptions of packages and their URLs. You could use wget to download based on those URLs (but make sure it is for the right Jetson and release). An exact copy of the installed “/var/whatever” directories of an actual Jetson would be a better choice than a lot of wget operations.
Note that dpkg on the command line can’t resolve dependencies. Using “apt-get” with local repositories you can do this. When JetPack installs packages, and if you use wget for manual install, you will always start with the “repo” packages. Once “repo” packages are in you can use ordinary “apt-get” commands even if there is no internet.