Rename jw.pkg.cmds.distro.backend.BackendCmd to Backend, because it's not necessarily a command, i.e. doesn't necessarily have a run() method. It's more of a distribution abstraction of the steps needed for for a specific command, the run() method itself is implemented in jw.pkg.cmds.distro.CmdXxx.
This commit is the beginning of a bigger move to change the distribution backend class hierarchy. At the end of this change set, the backend command should not derive the backend classes from a base specific to the respective distribution, but from an abstract base class specific to the command run. The distribution specifics are then going to be encapsulated in another class called "Util", an instance of which is going to be provided to the backend as .util member.
Move the body of BackendCmd.sudo() into a function. The rationale behind that is that its functionality is independent of the calling object for the most part, so having it in a function instead of a method is the more modular pattern.
apt-get install suggests it wants to be called with -f to clean up some mess left behind from a previous install. Adding -f in the hope add it to the install options by default. OTOH, it wants to be called that without arguments, not sure if always passing it along is a good idea.
The man page says:
-f, --fix-broken
Fix; attempt to correct a system with broken dependencies in place. This option, when used with install/remove, can omit any packages to permit APT to deduce a likely solution. If packages are specified, these have to completely correct the problem. The option is sometimes necessary when running APT for the first time; APT itself does not allow broken package dependencies to exist on a system. It is possible that a system's dependency structure can be so corrupt as to require manual intervention (which usually means using dpkg --remove to eliminate some of the offending packages). Use of this option together with -m may produce an error in some situations. Configuration Item: APT::Get::Fix-Broken.
Also turn the short options -yq into long options --yes --quiet for more obvious debugging if something goes awry.
Prepending --login to the argument list of BackendCmd.sudo() fails if run as root, because BackendCmd.sudo() detects that and leaves the /usr/bin/sudo out from the exec call. Fix that by adding an opts: list[str] parameter to sudo, defaulting to an empty list, with options that should be passed to /usr/bin/sudo.
Add a hand-coded __init__.py into jw.pkg.cmds.distro. Auto-generation works fine, but has to run before it can work. For a freshly downloaded toplevel Makefile / project-dirs-minimal.mk, the targets pkg-install-xxx-deps requires a working package manager without jw-pkg built.