91–100 of 354 posts
I may just not really be the target demo, or maybe am just a huge idiot, but I struggle to see the appeal, especially when you hear about the occasional horror stories about complex and/or broken environments, or the vim-like overhead to learn it properly.
> Nix, on the other hand, does have a concept of state. If you make a one-line change to a 200-line Nix configuration, it doesn’t have to re-do all the work from the other 199 lines. It can evaluate the state of the system against the configuration file and recognize that it just has to apply the one-line change. And that change usually happens in a few seconds. The author seems to have some misguided ideas about Nix…
Part of the difficulty is it means different things to different people. My colleague spent a whole lot of time trying to answer this question and ended up with this:
My main take away after spending some time learning about Nix is that it embraces the functional programming concept of a pure function.
If I give a function a certain set of inputs, it will return the same result every time, no matter what. Nix is about building software the same way, whether it’s your own software, someone else’s software, or your entire OS: You declare all your inputs explicitly and it will be built the same way every time.
What really mattered to them, regardless of how they were using Nix, was its ability to bring purely functional programming concepts to computing areas that were previously off-limits.
From that single idea you get a whole ecosystem of tools. We mainly covered the Nix language, the Nix Package Manager, and NixOS, but there’s also a continuous build system called Hydra, nix shell, and a deployment and provisioning tool called NixOps. Probably, there’s even more.
Another way someone else described Nix to me was "Gentoo for Haskell devs".
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nixpkgs doesn't use requirements.txt for whatever reason. (That reason probably being the utter brokenness and braindead state of Python packaging; Node packages work much better.)
You can package simple python projects, but as soon as there are too many huge deoendecies that use CPython and whatnot, it becomes impossible to generate the nix derivation. I just use imperative python-venv + pip install on those.
> Nix, on the other hand, does have a concept of state. If you make a one-line change to a 200-line Nix configuration, it doesn’t have to re-do all the work from the other 199 lines. It can evaluate the state of the system against the configuration file and recognize that it just has to apply the one-line change. And that change usually happens in a few seconds. The author seems to have some misguided ideas about Nix…
Earlier quoted context omitted.
I agree with everything but the last statement. This all comes down to: do you consider memoization to be state. I predict people's answers to this question will come from experience with memoization. Here's mine: I kept trying to get nix to build tensorflow locally, so that I would get the avx512 benefits of the big, but gpu-less machine I had. I hadn't realized some other derivation had already downloaded tensorflo…
Yes, you have unfortunately discovered that sometimes the hardware itself is an input that isn't always captured explicitly, but also isn't controlled for with sandboxing. Ideally enabling avx512 would be an explicit input to the tensorflow package, but based on your experience it sounds like this feature is detected during the build automatically. I hope that issues like this get better over time thanks to projects…
Looks like it sets e.g avx2 on the flags, forcing the package to be most compatible, thus removing the hardware state (the builder may or may not have avx512, ideally Nix packages should remove hardware autodetection to make it pure and consistent in face of cross-compiling).
It should indeed have an input in some way, e.g to add more flags. Then AIUI (still learning Nix) one would be able to call the package function with that input from the dependent package function, thus defining another package than the default one, which would be reified as its own specific derivation for that package to depend on.
https://github.com/NixOS/nixpkgs/blob/master/pkgs/developmen...
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Just to elaborate a bit for those not familiar to Nix (slightly simplified to exclude recent support for content addressing). Nix work with derivations, a derivation is basically a data structure that specifies how a package is built. Derivations are normally not created by hand but using a function (eg. stdenv.mkDerivation ). When you ask Nix to build a package, it hashes a normalized form of derivation data structu…
I agree with everything but the last statement. This all comes down to: do you consider memoization to be state. I predict people's answers to this question will come from experience with memoization. Here's mine: I kept trying to get nix to build tensorflow locally, so that I would get the avx512 benefits of the big, but gpu-less machine I had. I hadn't realized some other derivation had already downloaded tensorflo…
If this actually led to avx512 being enabled in the package, then that's a bug. Nix builds should not be dependant on the machine doing the compilation, all such autodetection should be disabled via configure flag or patched out.
Then, the right way to enable avx512 would be to pass some 'enable avx512 please' flag to the package's configure flags. Which would then trigger recompilation, without any 'disregard the nix store, in order to force the local build' options.
Earlier quoted context omitted.
Just to elaborate a bit for those not familiar to Nix (slightly simplified to exclude recent support for content addressing). Nix work with derivations, a derivation is basically a data structure that specifies how a package is built. Derivations are normally not created by hand but using a function (eg. stdenv.mkDerivation ). When you ask Nix to build a package, it hashes a normalized form of derivation data structu…
I agree with everything but the last statement. This all comes down to: do you consider memoization to be state. I predict people's answers to this question will come from experience with memoization. Here's mine: I kept trying to get nix to build tensorflow locally, so that I would get the avx512 benefits of the big, but gpu-less machine I had. I hadn't realized some other derivation had already downloaded tensorflo…
If so, then it makes so much more sense to me now.
Earlier quoted context omitted.
nixpkgs doesn't use requirements.txt for whatever reason. (That reason probably being the utter brokenness and braindead state of Python packaging; Node packages work much better.)
You can package simple python projects, but as soon as there are too many huge deoendecies that use CPython and whatnot, it becomes impossible to generate the nix derivation. I just use imperative python-venv + pip install on those.
(disclaimer: it's still rough but it does work)
https://github.com/NixOS/nixpkgs/tree/master/pkgs/servers/ho...
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Just in case: https://en.wikipedia.org/wiki/Functional_programming
I mean how Nix uses FP?