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Big fan of devenv. I moved away from a Docker-based setup for local development at work to devenv. At least on macOS, the Docker setup was making my machine too hot, and the performance wasn't really the best. With devenv, the transition took a bit of work but the utility and performance is fantastic.
I wish I knew whether Devenv has a conflict of interest with the Nix project. On /r/NixOS on Reddit, some of the people involved in the project just spam submissions related to Devenv instead of helping the community. One instance: https://www.reddit.com/r/NixOS/comments/194a4ln/comment/lnep...
I followed this relatively closely and there is no conflict of interest. There is competition, though. With flakes. That’s a good thing in general (competition is good) and in the case of flakes, specifically (flakes are lackluster).
It is the opposite of conflict of interest. Both devenv and the Nix community at large benefits from the growth of Nix.
You're flat out wrong. Devenv is the defacto standard solution in the Nix community for setting up per-project development environments and services, which is exactly what the linked submission asked for. Calling it a Nix fork like you did in your linked comment makes much sense as torching Debian for "shilling a Linux fork" just because they package patched kernels.
tl;dr: no.

This commenter is just wrong. denenv.nix pretty much is flake.nix + services. It has since grown more features, but this kind of use case is exactly its niche.

Devenv isn't a Nix fork and doesn't compete with Nix. Its scope is narrower and it's downstream of Nix. The code you write for configuring Devenv is ordinary Nix code. Its configuration system is a perfectly ordinary Nix module system.

There is a `devenv` CLI tool, and that CLI bundles a downstream soft fork of Nix that carries a few patches. Those patches exist to make it possible to read `devenv.nix` rather than `flake.nix` and use an easily programmatically editable yaml file for defining flake inputs. Other than that, all of the patches are just PRs that are open against mainline Nix that are included to speed up evaluation, notably the patchset for "lazy trees" or "source tree abstraction" (which is also in the Determinate Nix distribution of Nix).

But you can actually use the core features of Devenv (that is, the module system for configuring environments) without using the Devenv CLI or the patched evaluator. This isn't a hidden thing or a hack, either— it's documented on https://devenv.sh . It's always been this way, and isn't a paywall boundary or a trick. The whole of Devenv is open-source, and the vast majority of the code is Nix modules that you can use with any Nix implementation that you like (though flakes support makes it easier; Devenv's modules are exposed as flake-parts modules).

Hell, you can even use large subsets of devenv's functionality without using devenv at all. One of its key features is a Nix wrapper/integration for the pre-commit framework for managing git hooks. That whole subset of functionality is extremely loosely coupled to devenv, and lives in a separate repo. You can just import it as a flake-parts module with vanilla Nix without using devenv at all (i.e., not even the module system).

There's some code duplication with Nix (optional evaluator patches) and Nixpkgs (downstream release channel for guaranteeing integration with devenv's language configuration options, also optional (my team doesn't use it at all)), but it's extremely misleading to characterize Devenv as a fork of any Nix community projects including those two.

Just posting a link to the Devenv website is admittedly not a high-effort reply, but recommending Devenv is absolutely a fair reply to the post you linked. (Given that that post explicitly mentions not wanting to use Devenv, it definitely deserved a real conversation instead of what it got.)

PS: I'm not affiliated with devenv or Cachix. I just use it at work and know the code a little from times that I've filed bugs or submitted patches.

That is only partly correct. Devenv.sh misses outputs defining packages compared to flake.nix, i.e. there is no way to deterministically build the project as a nix package. It's the developer environment devenv competes with. Both can even work in tandem. Devenv for the devenv, flakes for the rest.
Sorry, I wasn't clear. Well, at least there wasn't a way. The newest update is now a step in that direction.
I have been doing this aspect manually, sometimes adding a flake.nix or using Devenv with flake.nix instead of devenv.nix.

If this can work well generally, it's a really slick integration. I'm really impressed with Devenv's velocity and usefulness overall.

If you haven't checked devenv out yet, you definitely should. Don't be intimidated by the breadth of the feature set, either! It's really easy to use just the bits you're interested in and grow your usage (or not) organically.

Does it cache dependency crates to nix store? Does it result to speed-up in builds?
Yes, it does vendor all the crates to Nix store.

It results into speed up in a way that if your application doesn't change, you'll just get the binary package.

That's why the two interfaces are exposed: one for development feedback cycle and one for distribution.

Yes, it caches compiled crates in the Nix store which significantly speeds up builds, especially for projects with large dependency trees.
how does it compare with the devbox project
We're aiming to take Nix to its most simple form, while devbox uses json for configuration.

Think of devenv as systemd of developer environments.

Don't a lot of people hate systemd?
This post is talking about building your project with Nix, and only tangentially about dev environments à la devbox.
devenv slaps. highly recommend.
It’s a bloody shame that Linux is incapable of reliable running software programs without layers and layers of disparate, competing abstractions.

I’m increasingly convinced that the mere existence of a package manager (for programs, not source code) is a sign of a failed platform design. The fact that it exists at all is a miserable nightmare.

Flatpak and Snap tried to make this better. But they do too much which just introduced new problems.

Steam does not have this problem. Download game, play game. Software is not that complicated.

> Steam does not have this problem. Download game, play game. Software is not that complicated.

Steam on Linux essentially has its own "package manager" which uses containerized runtimes: https://gitlab.steamos.cloud/steamrt/steam-runtime-tools

The Steam Linux Runtime is pretty bare bones. Their most recent runtime hasn’t been updated in 4 years. That’s quite different.
> Their most recent runtime hasn’t been updated in 4 years. That’s quite different.

Bad, even.

False. The exact opposite of bad.

The “system” should provide the barest minimum of libraries. Programs should ship as many of their dependencies as is technically feasible.

Oh what’s that? Are crying about security updates? Yeah well unfortunately you shipped everything in a Docker container so you need to rebuild and redeploy all of your hierarchical images anyways.

> False. The exact opposite of bad.

I don't mind stable base systems, I don't mind slow and well tested updates, I actively like holding stable ABIs, but if you haven't updated anything in 4 years, then you are missing bug and security fixes. Not everything needs to be Arch, but this opposite extreme is also bad.

> The “system” should provide the barest minimum of libraries. Programs should ship as many of their dependencies as is technically feasible.

And then application developers fail to update their vendored dependencies, and thereby leave their users exposed to vulnerabilities. (This isn't hypothetical, it's a thing that has happened.) No, thank you.

>Oh what’s that? Are crying about security updates? Yeah well unfortunately you shipped everything in a Docker container so you need to rebuild and redeploy all of your hierarchical images anyways.

So... are you arguing that we do need to ship everything vendored in so that it can't be updated, or that we need to actually break out packages to be managed independently (like every major Linux distribution does)? Because you appear to have advocated for vendoring everything, and then immediately turned around to criticize the situation where things get vendored in.

> So... are you arguing that we do need to ship everything vendored in so that it can't be updated,

I’m arguing that the prevalence of Docker is strong evidence that the “Linux model” has fundamentally failed.

Many people disagree with that claim and think that TheLinuxModel is good actually. However I point that these people almost definitely make extensive use of Docker. And that Docker (or similar) are actually necessary to reliably run programs on Linux because TheLinuxModel is so bad and has failed so badly.

If you believe in TheLinuxModel and also do not use Docker to deploy your software then you are, in the year 2025, a very rare outlier.

Personally, I am very pro ShipYourFuckingDependencies. But I also dont think that deploying a program should be much more complicated than sharing an uncompressed zip file. Docker adds a lot of crusting. Packaging images/zips/deployments should be near instantaneous.

> I don't mind stable base systems, I don't mind slow and well tested updates, I actively like holding stable ABIs, but if you haven't updated anything in 4 years, then you are missing bug and security fixes.

I'm not sure GP's claim here about the runtime not changing in 4 years is actually true. There hasn't been a version number bump, but files in the runtime have certainly changed since it's initial release in 2021, right? See: https://steamdb.info/app/1628350/patchnotes/

It looks to me like it gets updated all the time, but they just don't change the version number because the updates don't affect compatibility. It's kinda opaque though, so I'm not totally sure.

> Programs should ship as many of their dependencies as is technically feasible.

Shipping in a container just is "ship[ping] as many [...] dependencies as is technically feasible". It's "all of them except the kernel". The "barest minimum of libraries" is none.

Someone who's using Docker is already doing what you're describing anyway. So why are you scolding them as if they aren't?

I’m scolding the person who says vendoring dependencies is bad… but then uses docker for everything anyways.
> I’m increasingly convinced that the mere existence of a package manager (for programs, not source code) is a sign of a failed platform design.

Nix is a build system for source code, similar to make. It is such a robust build system that it also can be used as a package manager with a binary cache

Does Steam let you control the whole dependency tree of your software, including modifying any part of it and rebuilding from source as necessary, or pushing it to a whole other machine?

Real life software is much more than just downloading a game and running it.

Pushing to another machine? Yes. By strict definition. Steam exists to sell pre-compiled proprietary programs for dollars.

Rebuilding? No. Linux package management is so-so at allowing you to compile programs. But they’re dogshit garbage at helping you reliably run that program. Docker exists because Linux can’t run software.

Docker (and also Nix) exists because it's not trivial to manage the whole environment needed to run an application.

There's a reason everyone uses it for ops these days, and not some Windows thing.

Yes. The reason is that Linux made very bad design decisions.

> it’s not trivial to manage the whole environment needed to run the application

This is a distinctly Linux problem. Despite what Linux would lead you to believe it is not actually hard to run a computer program.

Ok then where is the amazing non Linux deployment solution that everyone uses instead?
> Real life software is much more than just downloading a game and running it.

Real life software outside of Linux is pretty much just downloading and running it. Only in Linux we don't have a single stable OS ABI, forcing us to find the correct package for our specific distro, or to package the software ourselves.

Maybe for desktop use but when you want to deploy something to your server it's a bit more complicated than that.
> I’m increasingly convinced that the mere existence of a package manager (for programs, not source code) is a sign of a failed platform design

> Steam does not have this problem. Download game, play game.

These statements seem contradictory. Steam is a package manager. So is the Apple App Store. Sure, they have different UX than, say, apt/dnf/brew/apk/chocolatey, but they're conceptually package managers.

Given that, I'm unclear what the gripe is (though I'm totally down to rip on Snap/Flatpak; I won't rant here, but I did elsewhere: https://news.ycombinator.com/item?id=44069483). Is the issue with OS/vendor-maintained package managers? Or is the issue with package installers that invoke really complicated build systems at install time (e.g. package managers that install from source)?

This is getting into semantics. Personally I would not consider downloading a zip file from a GitHub releases page in a web browser to be using a “package manager”. But someone could try and make that argument.

None of this has formal definitions which makes it difficult to discuss.

Your rant on Snap/Flatpak was great.

The core gripe is that I want running computer programs on Linux to be easy and reliable. It is not. MacOS and Windows are far more reliable, and they don’t require (imho) package managers to do it.

> The core gripe is that I want running computer programs on Linux to be easy and reliable. It is not.

No argument here.

What's interesting, though, is that package managers on Linux are the attempted solution to that problem. Without them, hand-managing dependencies and dependency discovery via the "download a zipfile from GitHub" approach just falls apart: said zipfile often wants to link against other libraries when it launches.

Windows (and runtimes like Golang) take a batteries-included approach by vendoring many/most dependency artifacts with binary distributions. MacOS app bundles do a bit of that, and also have a really consistent story about what system-level dependencies are available (which is only a feasible approach for MacOS because there's a single maintainer and distributor of the system).

But even on those platforms, things break down a lot! There are all sorts of problems for various Windows apps that need to be solved by "acquire so-and-so.dll and copy it into this app's install folder, or else its vendored version of that dll will break on your system". Homebrew on MacOS exists (and has highly variable complexity levels re: installation/dependency discovery) precisely because the amount of labor required to participate in the nice app bundle/MacOS native-app ecosystem is too great for many developers.

That said, there's not really a punchline here. It's complicated, I guess?

> Your rant on Snap/Flatpak was great.

Thank you!