On Tue 27 Oct 2020 at 15:05:36 (+0200), Andrei POPESCU wrote: > On Lu, 26 oct 20, 09:55:00, John Hasler wrote: > > Andrei writes: > > > dpkg does its own dependency checking, in addition to APT (the > > > software, not the command), and will prevent any inconsistencies > > > unless you use one of the --force switches. > > > > What it does not do is resolve dependencies. Apt recursively resolves > > dependencies, installing them as required. It also detects conflicts > > and offers to resolve them as well as breaking loops. > > dpkg can only work with the set of .deb files that were passed on the > command line. > > If all dependencies are included (or already installed), fine, otherwise > it will bail out as it doesn't (by design) have the capability to search > for them in repositories and download them (if this is what you mean by > resolving). > > I believe someone demonstrated quite recently on list that dpkg has some > limits in the number and/or combination of packages it can deal with at > once, so APT might have to pass them in smaller chunks and/or specific > order (in case of Pre-Depends: maybe?). > > > Dpkg is safe but can be rather frustrating. > > As far as I'm concerned it does just fine what it was designed to do.
Years ago, I used to do mega installs with dpkg, copying the contents of /var/cache/apt/archives/ from one machine onto a caddy, and then installing them all on another. I'm probably the person who recently demonstrated dpkg's (in)ability to cleanly install 1558 packages simultaneously without help: https://lists.debian.org/debian-user/2020/07/msg00032.html (its References are all dead links because they fall in the previous month.) This followed a demonstration of apt-get's reversibility: specifying 271 "top-level" packages that resulted in 1558 being installed altogether, and all 1558 being cleanly purged again. Cheers, David.
