Are they so different that it's justified to have so many different distributions? So far I guess that different package manager are the reason that divides the linux community. One may be on KDE and one on GNOME but they can use each other's packages but usually you are bound to one manager
I wouldn't worry too much about the package manager, just worry about whether the distro has a good package repository. If it has all the software you want to use, then use it. In my opinion, most package managers (dnf, apt, pacman, xbmp) are basically the same, and you would only notice a big difference if you ever tried to make your own package for your own software.
That said, a few package managers are very different from all the rest:
prt-get
": simple and stupid: just downloads and installs tar archives.emerge
": builds all software from source code when you install it. This provides some guarantees that the source code was not tampered with by the distro maintainers, this is great if you need to review all of the source code that is running on your system, but terrible for most people who don't want to spend so much computing power on compiling stuff every time you do a software update.My personal preference: I use ordinary Debian or Ubuntu to install the critical software that needs to be stable and reliable, and I use Guix OS on the side to install the bleeding-edge things that might break a lot.
I couldn't disagree more! Package managers are actually the only thing which differentiates distributions by a large margin. Syntax should be intuitive, download/updates fast and reliable. Also when watching git repositories for new software alternatives, you e.g. see often packages for good package managers, whereas you need to go some extra mile for "stable" package managers.
But I would say these are not features of the package manager software, rather they are features of the package repository, that is, the online service that provides the packages. It doesn't matter if you use Apt, DNF, Pacman, if the package repo is slow, fully of packages that haven't been built right, the package manager software won't do much to make it better.
But like I said, a few package manager are really unique, like Gentoo Emerge, Crux Prt-Get, and Nix and Guix.
Can you decouple a package manager from its repository like that? And even if, is that a real world example?
Yes.
Ubuntu and debian both use apt, but differing repos. Different versions of ubuntu/debian use different repos, with newer/older software.
Ubuntu and Debian differences...don't see your point here. Nobody in Arch uses apt? Nobody on ubuntu uses pacman. If you use pacman you are using Arch repositories.
Incorrect. There is manjaro, but there also is msys2, a windows program with the goal of making linux tools available on windows by recompiling all of them. That's very far from the arch philosophy and repos.
And ubuntu and debian have massively different repositories. One of them gives you the actual firefox package, and the other installs firefox via a closed source backend, app store called snap, when you attempt to install firefox using apt.
And then there is also the version differences, like debian stable is going to have much older software than ubuntu.
Thanks for pulling corner cases from dark places... not sure if we misunderstand but my point was as written, you use the package manager/repository which ships with your distro. So the original quote was:
Also, bit part of Portage (Gentoo "emerge") is being able to 'flag out' parts of the package out (or in) to the compilation.
Let's say you want to not have telemetry in your packages. So you set '-telemetry' globally, and each package that has known telemetry parts will not compile locally - so it can not be turned on (unless it's hidden really well).
Or you want to use pulseaudio? You can flag it globally, or for specific packages. That way you can influence software you install without knowing much about anything build-related - the work is done by the repository maintainers.
They won't be able to pry Gentoo from my cold dead hands. Arch, Nix/Guix can suck it, all my money goes to the Gentoo