mirror of https://github.com/foo-dogsquared/wiki.git synced 2025-01-31 07:57:57 +00:00

Gabriel Arazas b088086b06 Merge evergreen notes into the notebook

Now, it's all under the notebook umbrella. Seems to be appropriate as it
is just my notes after all.

I also updated some notes from there. I didn't keep track of what it is
this time. Something about more learning notes extracted from my
"Learning how to learn" course notes and then some. Lack of time and
hurriness just makes it difficult to track but it should be under
version control already.

2021-07-21 16:28:07 +08:00

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Nix flakes

As of 2021-06-30, the version used for this note is at v2.3 so it needs to be invoked with the unstable version.

similar to Guix channels
a collection of packages and functions while making it easy to configure Nix declaratively
replaces the traditional Nix channels since fully reproducing an environment with Nix requires special care in practice; plus, there's no standard way of composing projects with Nix
as of 2021-06-30, this is on the unstable version of the Nix package manager and needs some additional configuration

why flakes?

provides a structure for discoverability
makes 100% reproducibility a little easier with Nix
in case you're using NixOS, it also provides an easier way to extend it with third-party custom modules

Here's an example to interact with a flake. It will show the entire outputs of a flake as well as the normalized version of the flake object.

#! nix-shell -i bash -p nixUnstable
nix --experimental-features 'nix-command flakes' flake show <<flake-sample-object()>> | sed -e "s/\x1b\[.\{1,5\}m//g"

github:edolstra/dwarffs/f691e2c991e75edb22836f1dbe632c40324215c5
├───checks
│   ├───aarch64-linux
│   │   ├───build: derivation 'dwarffs-0.1.20210121.f691e2c'
│   │   └───test: derivation 'vm-test-run-unnamed'
│   ├───i686-linux
│   │   ├───build: derivation 'dwarffs-0.1.20210121.f691e2c'
│   │   └───test: derivation 'vm-test-run-unnamed'
│   └───x86_64-linux
│       ├───build: derivation 'dwarffs-0.1.20210121.f691e2c'
│       └───test: derivation 'vm-test-run-unnamed'
├───defaultPackage
│   ├───aarch64-linux: package 'dwarffs-0.1.20210121.f691e2c'
│   ├───i686-linux: package 'dwarffs-0.1.20210121.f691e2c'
│   └───x86_64-linux: package 'dwarffs-0.1.20210121.f691e2c'
├───nixosModules
│   └───dwarffs: NixOS module
└───overlay: Nixpkgs overlay

Let's build from one of the outputs of call_flake-sample-object().

#! nix-shell -i bash -p nixUnstable
nix --experimental-features 'nix-command flakes' build 'github:edolstra/dwarffs#checks.aarch64-linux.build'

nix --experimental-features 'nix-command flakes' shell 'github:edolstra/dwarffs' --command dwarffs --version

fusermount version: 2.9.9

For full reproducibility, you can refer to specific point of a flake (e.g., commit).

To easily get a pinned URL, you can run flake metadata subcommand.

#! nix-shell -i bash -p nixUnstable
nix --experimental-features 'nix-command flakes' flake metadata 'github:edolstra/dwarffs' | sed -e "s/\x1b\[.\{1,5\}m//g"

Resolved URL:  github:edolstra/dwarffs
Locked URL:    github:edolstra/dwarffs/f691e2c991e75edb22836f1dbe632c40324215c5
Description:   A filesystem that fetches DWARF debug info from the Internet on demand
Path:          /nix/store/769s05vjydmc2lcf6b02az28wsa9ixh1-source
Revision:      f691e2c991e75edb22836f1dbe632c40324215c5
Last modified: 2021-01-21 22:41:26
Inputs:
├───nix: github:NixOS/nix/6254b1f5d298ff73127d7b0f0da48f142bdc753c
│   ├───lowdown-src: github:kristapsdz/lowdown/1705b4a26fbf065d9574dce47a94e8c7c79e052f
│   └───nixpkgs: github:NixOS/nixpkgs/ad0d20345219790533ebe06571f82ed6b034db31
└───nixpkgs follows input 'nix/nixpkgs'

#! nix-shell -i bash -p nixUnstable
nix --experimental-features 'nix-command flakes' shell github:edolstra/dwarffs/f691e2c991e75edb22836f1dbe632c40324215c5 --command dwarffs --version

fusermount version: 2.9.9

4.2 KiB Raw Blame History

Nix flakes

4.2 KiB

Raw Blame History