samueldr / nix-universal-prefetch

nix-universal-prefetch

This uses nix and nixpkgs to actually run the prefetch operation, then read the error message to figure out the desired hash.

The output is only of the hash when it works, allowing it to be (ab)used in an automated manner.

When another error happens, the standard error output will be printed.

Installing

git clone https://github.com/samueldr/nix-universal-prefetch.git
cd nix-universal-prefetch
nix-env -if .

Testing

.../nix-universal-prefetch $ nix-build ./test

Limitations

It cannot print the complete list of arguments for composed fetchers (most fetchers are composed).

However, passing those unlisted additional arguments to those fetchers will work.

---

Example

 $ nix-universal-prefetch -l
Fetchers:
 - fetchCrate
 - fetchDockerConfig
 - fetchDockerLayer
 - fetchFromBitbucket
 - fetchFromGitHub
 - fetchFromGitLab
 - fetchFromRepoOrCz
 - fetchFromSavannah
 - fetchHex
 - fetchMavenArtifact
 - fetchNuGet
 - fetchRepoProject
 - fetchbower
 - fetchbzr
 - fetchcvs
 - fetchdarcs
 - fetchdocker
 - fetchegg
 - fetchfossil
 - fetchgit
 - fetchgitLocal
 - fetchgitPrivate
 - fetchgx
 - fetchhg
 - fetchipfs
 - fetchmtn
 - fetchpatch
 - fetchs3
 - fetchsvn
 - fetchsvnrevision
 - fetchsvnssh
 - fetchurl
 - fetchurlBoot
 - fetchzip

 $ nix-universal-prefetch fetchFromGitHub --help
fetchFromGitHub: [options]
        --fetchSubmodules=VALUE
        --githubBase=VALUE
        --name=VALUE
        --owner=VALUE
        --private=VALUE
        --repo=VALUE
        --rev=VALUE
        --varPrefix=VALUE

 $ nix-universal-prefetch fetchFromGitHub --owner NixOS --repo nixpkgs
error: 'fetchFromGitHub' at /etc/nixos/nixpkgs/pkgs/top-level/all-packages.nix:236:21 called without required argument 'rev', at (string):1:2

 $ nix-universal-prefetch fetchFromGitHub --owner NixOS --repo nixpkgs --rev master
04i1xrzyl3i3b1kmfx6f5z78sc66hwzyxd3v6i4zfqavvarw3w6s