1_gnutar.nix

stdenv.mkDerivation rec {
  name = "gnutar-${version}";
  version = "1.30-unstable";

  src = fetchgit {
    url = "http://git.savannah.gnu.org/r/tar.git";
    rev = "7340f67b9860ea0531c1450e5aa261c50f67165d";
    sha256 = "03q5vglkx891asl8jmn850vkks6bkv5np6n9abqfwjgd9i32h10h";
  };

  # avoid retaining reference to CF during stdenv bootstrap
  configureFlags = stdenv.lib.optionals stdenv.isDarwin [
    "gt_cv_func_CFPreferencesCopyAppValue=no"
    "gt_cv_func_CFLocaleCopyCurrent=no"
  ];

2_nix-build.sh

nix-build -A gnutar --show-trace
error: while evaluating the attribute ‘src’ of the derivation ‘gnutar-1.30-unstable’ at /home/nequi/dev/nixpkgs/pkgs/tools/archivers/gnutar/default.nix:4:3:
while evaluating the attribute ‘nativeBuildInputs’ of the derivation ‘tar-7340f67’ at /home/nequi/dev/nixpkgs/pkgs/build-support/fetchgit/default.nix:46:10:
while evaluating the attribute ‘nativeBuildInputs’ of the derivation ‘git-2.10.1’ at /home/nequi/dev/nixpkgs/pkgs/applications/version-management/git-and-tools/git/default.nix:19:3:
while evaluating the attribute ‘patches’ of the derivation ‘cpio-2.12’ at /home/nequi/dev/nixpkgs/pkgs/tools/archivers/cpio/default.nix:7:10:
while evaluating anonymous function at /home/nequi/dev/nixpkgs/pkgs/build-support/fetchpatch/default.nix:8:1, called from /home/nequi/dev/nixpkgs/pkgs/tools/archivers/cpio/default.nix:15:6:
anonymous function at /home/nequi/dev/nixpkgs/pkgs/build-support/fetchurl/boot.nix:5:1 called with unexpected argument ‘name’, at /home/nequi/dev/nixpkgs/pkgs/build-support/fetchpatch/default.nix:10:1

3_fetchurl_boot.nix

let mirrors = import ./mirrors.nix; in

{ system }:

{ url ? builtins.head urls
, urls ? []
, sha256
, ...
}:

import <nix/fetchurl.nix> {
  inherit system sha256;

  url =
    # Handle mirror:// URIs. Since <nix/fetchurl.nix> currently
    # supports only one URI, use the first listed mirror.
    let m = builtins.match "mirror://([a-z]+)/(.*)" url; in
    if m == null then url
    else builtins.head (mirrors.${builtins.elemAt m 0}) + (builtins.elemAt m 1);
}

4_nix-build.sh

nix-build -A gnutar
these derivations will be built:
  /nix/store/xw7fkp0nizibhgzy1i0mrbv0iqxk703i-gnutar-1.30-unstable.drv
building path(s) ‘/nix/store/7ibiy9bf5maidla7dz5rchv0djsrm7yr-gnutar-1.30-unstable-info’, ‘/nix/store/rdwmfxzp1f7n62m623nnm80gpd5yn318-gnutar-1.30-unstable’
unpacking sources
unpacking source archive /nix/store/dy4dsa78yb5zzy2l5zpayd2fnkb4nn3l-tar-7340f67
source root is tar-7340f67
patching sources
configuring
grep: Invalid range end
no configure script, doing nothing
building
no Makefile, doing nothing
installing
install flags: install           pkgconfigdir=/nix/store/rdwmfxzp1f7n62m623nnm80gpd5yn318-gnutar-1.30-unstable/lib/pkgconfig         m4datadir=/nix/store/rdwmfxzp1f7n62m623nnm80gpd5yn318-gnutar-1.30-unstable/share/aclocal aclocaldir=/nix/store/rdwmfxzp1f7n62m623nnm80gpd5yn318-gnutar-1.30-unstable/share/aclocal          
make: *** No rule to make target 'install'.  Stop.
builder for ‘/nix/store/xw7fkp0nizibhgzy1i0mrbv0iqxk703i-gnutar-1.30-unstable.drv’ failed with exit code 2
error: build of ‘/nix/store/xw7fkp0nizibhgzy1i0mrbv0iqxk703i-gnutar-1.30-unstable.drv’ failed

Context:

1. Changed the fetchurl to fetchgit
2. nix-build complains about a chain of things, which lead me back to fetchurl/boot.nix
3. Added a , ... argument to the function there "fixes" the issue
4. C build does not work; and I have no idea about C builds :)