Every distribution has the exact same problems that are impossible to prevent. It's all about the inherent limitations of how software is developed and run in operating systems today. All this stuff about 'solving dependency hell' and dependency paths tied up with merkle trees doesn't change the fact that you can't use two completely different libraries in one application at the same time, nor shell out to two incompatible versions of a binary from the same application. It is only possible if the software itself is designed to do that, using the features of a dynamic linker that allow linking in multiple versions of the same function and specifying which version you're calling from what source function. We don't actually need a new package manager or distribution at all, because they can't solve one of the most fundamental problems - only developing software differently can do that.
You should spend more time in the Nix community, because actually people are very aware of these limitations. For C packages, yes the best we can easily do is ensure each binary has coherent library choices, but allow mixing libraries in different binaries. That is still useful, though!
That said, you underestimate the power of being able to hack on any dependency -- for real purpose of Nix is to defeat Conway's law, allowing any person to work on any codebase. It would be quite easy to fork the linker/loader to try out some experiment, or even just do some per-package symbol mangling, for example. I wouldn't want to try that experiment with any other distro, because it would be too hard to make my modification and then put everything together again!
Do you find you need to make experimental changes to the linker often?
Back when I was a Gentoo user, I too bought the story that being able to re-emerge my whole system was some kind of performance or configuration boon. Eventually I realized that I just wanted to use my computer to get through life, that literally any operating system would work, and that any experimental hacks could simply be done when they were needed rather than trying to manage an over-complicated, poorly-supported hobby OS.
I use Ubuntu now. It sucks. But I spend my time on doing real world things now, rather than constantly tweaking my computer to eventually do a real world thing.
For work I use containers with any distribution at all. They all have the same result in a container.
> I too bought the story that being able to re-emerge my whole system was some kind of performance or configuration boon. Eventually I realized that I just wanted to use my computer to get through life...
I don't have fun constantly mucking with my settings either. That novelty long wore off long ago, like with most people who have used Linux 10+ years.
I do however get a benefit being able to set up my same config on multiple machines. For example, recently, I switched from XMonad to sway on my work computer, which necessitated a bunch of config changes. I then synced those changes over to my personal machine with https://github.com/nix-community/home-manager .
C.f. my phone just died, and I got a new android, and the android backup/sync situation gets worse and worse, and it will be a huge pain in the ass fixing my phone so i can hopefully move a few more account settings, 2FAs, etc. over.
The moral of the story is that when I do need to configure something, I want to do it once. Sysadmining repetitively is infuriating.
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The linker thing is quite different. I still do like programming (as opposed to sysadmining) for fun, and I want the tools to suck less. I also find infrastructure fun and interesting, be it computer or real world. I am a fairly prolific contributor to the Nix ecosystem, not because what I necessary want to do by myself on my own machine, but simply because I enjoy making the stuff better (and this hobby also sometimes becomes current task on the job, too).
Nix starts from a strong baseline of "sound" builds --- anything that is not sand-boxed, and therefore unlikely to be reproducible / cached correctly now pisses me off a shitty software that doesn't respect by time. The goal is to build on that foundation and also make Nix builds more incremental, so we have both a reliable and tight debug loop. Ultimately I want to see my work and the Nix community at large swamp the rest of the computing world with the productivity that is unleashed and when we stop crippling ourselves with shitty tools.
The flip side is that since goal is social, I have 0 interest in solo dog-fooding. I only use my PRs which I merged upstream; whatever benefits they would bring are certainly outweighed by the costs of living on forks all by oneself.
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If not being totally relatable (I rarely find people interested infra changes that don't immediately benefit them) hopefully it is at least clearly distinct from "building out my person nerd terrarium" customizing the computer as individualistic self-expression.
Sorry, but Nix is a total waste of time.