[thomastjeffery]

Your second point is exactly what happened to me here: https://github.com/NixOS/nixpkgs/issues/9682

Sure, pinning is great, and the ability to ignore versions seems to be a great design goal. Unfortunately, that design goal is shoved down the throats of users, and makes a very messy - and difficult to traverse or use - namespace where different versions are just thrown in the name without another thought.

NixOS is my favorite Linux distro, and the only OS currently installed on my laptop. It's also frustrating in unnecessary ways.

[jcrben]

Thanks for linking that discussion. I'm surprised that you didn't get acknowledgment of the UX issues there, and I'm pretty sure there are people who would like to see the UX situation improve. It just takes work... this release represents a large step forward in UX. I think they'd welcome your input in making 3.0 better! I made a couple small docs fixes the other day.

[lucideer]

> Your second point is exactly what happened to me here:

Perhaps I'm wrong but I think I not only agree with the nix dev in that thread, but I also think it seems kind of the opposite case to what the gp was describing in their second point.

From the gp's post:

> Their technical foundation is so far ahead of mainstream systems [...] they've forgotten how to live a day in the shoes of a mere mortal. Try pointing out flaws in the user experience [...] If you want to spread the amazing potential of Nix to everyone, then you need to compromise with a flawed, imperfect world. You need to meet users [...]

The definition of "user" can be vague, but if you're talking about "mainstream" and "mere mortals", I don't think setting up Haskell dev environments are the primary use-case. As was commented in that thread:

> It's what most distros do. (Only gentoo diverges from the big ones [...]

Favouring simplicity and focusing on supporting only production environments seems exactly the kind of user-focused pragmatism the gp would rather.

I'm not on Nix (yet), I use Debian; I use Apt to maintain my kernel, browser, video player. I don't use it to install dev dependencies.

[thomastjeffery]

> setting up Haskell dev environments

What I was complaining about was the difficulty installing a specific package version. That's trivial with other build systems, but not Nix.

> I don't use [package managers] to install dev dependencies.

I'm under the impression that most people do. Either way, I see the main advantage of using Nix to be setting up dev environments without installing a bunch of global packages, or dealing with a mess of files. Unfortunately, as a user, I find it to be much more of a hassle than it needs to be.

[lucideer]

When quoting me, you changed my wording to suit your own argument, which seems to imply you get my point but are choosing to ignore it. (You swapped out "Apt", my distribution package manager, for "[package managers]", which would include both distro and dev language package managers. The latter are for devs, the former for users)

[thomastjeffery]

It certainly reads like "it" was to mean "the aptitude package manager" to me.

If you like to use a separate package manager for libraries/etc. that is fine. That is not something I enjoy doing.

Using Debian, I would frequently install a build dependency, and forget I cluttered my install doing so, leaving a package I don't care about or remember to be updated, and possibly break future installs. I read about nix-shell, and have been using NixOS ever since.

NixOS has clear room for improvement, but, unfortunately, some of the devs are adamant that it cannot - worse: should not - be done.

[lucideer]

> It certainly reads like "it" was to mean "the aptitude package manager" to me.

The aptitude package manager is the package manager for the Debian operating system. It is for managing packages that make your OS run. Unless you're defining multiple repo versions in your sources.list and using apt pinning, it typically gives you one version of the latest supported software. Other distro/OS package managers do the same. Even Homebrew for macOS deletes older versions and makes them inaccessible. NixOS' package manager does the same here. This is very typical. Portage is an exception.

Separately, Cabal is a package manager for development dependencies for the Haskell programming ecosystem. This is what you should use for setting up such a dev environment. It is specifically developed with this in mind.

Asking your OS package manager to additionally manage the ecosystem of every programming language you may want to develop in seems a bit out of scope, no?

> NixOS has clear room for improvement, but, unfortunately, some of the devs are adamant that it cannot - worse: should not - be done.

Your definition of "improvement" seems to be to handle use-cases it isn't intended for and for which there are specialised package managers, likely introducing huge complexity and spreading resources thin. This seems like something that could also be a disimprovement.

[e12e]

> Separately, Cabal is a package manager for development dependencies for the Haskell programming ecosystem.

And cargo/rustup, go for golang, pip for python, gem/bundle for ruby...

But they all tend to depend on parts of the Os - or their own c compile chain to compile their own version of c libs.

Which leads to the question of how you most easily write a tool in haskell that you can distribute as a deb package.

Saying that "for haskell, playing nice with Perl's ssl-dependencies is hard, so we won't bother" is one approach. It certainly is one way to use up additional resources provided by moore's law: no shared libraries, just thousands of copies of statically linked strlen-functions, in thousands of chroots. (also, hello there, docker).

Snapshots and isolation are great tools, but I don't think it's clear cut what's best yet. Especially when you want to ensure you're not running code with well-known vulnerabilities - be that in bash, ssl keygen, or mallloc.

[thomastjeffery]

> Asking your OS package manager to additionally manage the ecosystem of every programming language you may want to develop in seems a bit out of scope, no?

For apt? maybe. For Nix? no.

Nix doesn't install packages, it creates environments. NixOS considers one environment to be the main operating system. That is the main feature of Nix: self-contained reproducible environments.

Because it is so well suited to the task, nix provides all the packages provided by Hackage, sorted into separate namespaces for each supported version of GHC. Each namespace, however, supports only one package version per package; so any packages where it makes sense to provide multiple versions has loosely adopted the name_version naming scheme as a workaround.

Out of frustration, I searched for an answer why this is the case, and found an issue someone else had already discussed at length, only to find a dead end: the issue was discarded (not honestly considered). I then commented at length to explain my line of thinking, only to hear excuses for keeping the status quo, rather than actual help or discussion. The developers commenting on the issue were hung up on their preference for "pinning", and didn't want to consider the namespace mess I have such issue with.

It seems you share the same attitude that changes cannot be done - not because you are certain that is the case, but because you don't believe it should be. There is no reason behind this attitude, and I frankly have no patience for it.

If you want to discuss this problem and any related nuances, I am happy to do so. Please do not naively tell me that my perspective doesn't exist, or cannot make sense.

[jcrites]

It seems like Nix could benefit from a first-class concept for pinning the channel and managing updates to the channel. To achieve build reproducibility, the default outcome of checking out a project and building it should be to get the same result as everyone else who does so at the same project revision. I'd expect there to be a way to take a snapshot of the channel and lock those versions in the project until you're ready to upgrade.

I have tinkered a lot with Nix, but have not used it for any production system. I'd be reluctant to use Nix in production if there wasn't a good way to pin the channel, so that everyone who is developing on a project sees precisely the same versions as each other, and everyone who is patching a specific version of a project sees the same version as what's currently deployed. In my opinion, this should be the default behavior and not something that you have to go out of your way to achieve.

Maybe you could model this as something like a "channel fork" or "user channel". When you create a new project, you also create a channel for it that inherits from an existing channel, except that the versions of all packages are pinned and you can control the way in which changes make their way into your user channel from the upstream.

My company has a proprietary technology that's similar to Nix, and we tackle the build reproducibility problem in this way, by making it easy to branch off the main channel and control how updates make their way into it (which is like a merge). The default behavior when creating a project is to also create a project-specific channel, derived from the upstream, company-wide channel. Dependencies are declared at the major version level only, and versioning beneath that level happens implicitly via the project channel.

In this system you think of all channels as having revisions. Developers can control how their channel merges in changes from its upstream channel, which provides stability and reproducibility: until you merge and release a new version, `my-channel` always references exactly the same package versions for all developers. The default behavior of channels is to merge new versions from the upstream channel periodically, but developers can decide what's right for them, whether staying on the bleeding edge or prizing stability.

Software builds, releases, and deployments always happen in the context of a specific channel revision (`my-channel@revision`), which can be named and referenced, so if necessary you can inspect or replicate exactly the code that's part of a colleague's configuration or a production system. Not just approximately but exactly, for every package involved down to `gcc` and `glibc`. It's easy to create a workspace with the package versions specified by `my-channel@12345`.

By further tracking which source code commit hash corresponds to each package release in the channel, you can trivially look up the exact source of all packages (my-channel@12345 -> FooPackage@a1b2c3d4). Extremely useful! When you work and version things in this way, you hardly need version numbers beneath the major version level.

I suppose it's reasonable that the Nix project doesn't want to host binary versions of lots of old packages to make this use-case fast. In that case, I'd want it to be easy to clone the binary version of those dependencies and source them locally. Maybe this could operate as something like a caching proxy in front of Nixpkgs, that will store my own permanent copy of any package that I access or build. On the other hand, keeping builds forever is expensive, so perhaps this is an opportunity for Nix to provide a commercial offering with private channel hosting and a package cache with infinite TTL.

[catern]

From a technological standpoint, it's easy to pin the channel. It's as simple as creating a file like this in your project: https://github.com/catern/nix-utils/blob/master/pkgs.nix

And importing that file whenever you want to use packages from nixpkgs: https://github.com/catern/nix-utils/blob/master/default.nix

If you want to have a separate channel which you can update on your own, just fork nixpkgs on Github and point your pkgs.nix at your fork.

The Nix binary cache keeps every version of every binary in nixpkgs that's ever been built on the Nix project's build servers. (Note that that's not absolutely everything in nixpkgs, since some things aren't built centrally on the build servers for various reasons, but it's most things.)

However, I might be misunderstanding. Was there some other feature or ergonomics benefit that you were looking for?

[pxc]

> I suppose it's reasonable that the Nix project doesn't want to host binary versions of lots of old packages to make this use-case fast. In that case, I'd want it to be easy to clone the binary version of those dependencies and source them locally. Maybe this could operate as something like a caching proxy in front of Nixpkgs, that will store my own permanent copy of any package that I access or build.

I don't know when it will be ready, but some work has gone into backing Nix caches with IPFS, and it looks like it could be a really cool solution for making it easy to share a cache for 'extra' or 'old' packages without much infrastructure work on the parts of users.

https://github.com/NixOS/nix/issues/859