nixpkgs/nixos/modules/installer/cd-dvd/channel.nix
Domen Kožar 75284b09e1 Fix ISO building from a channel
Building config.system.build.isoImage would fail with the following
error using the channel:

  ln: failed to create symbolic link
'/nix/store/zz0hzi5imrg4927v6f8mv281qs6v6pbq-nixos-16.03pre69762.e916273/nixos/nixpkgs/.': File exists

The fix skips symlink as it already exists if the channel
nixpkgs copy is used.

Fixes #10367
2016-01-16 21:58:40 +01:00

45 lines
1.4 KiB
Nix

# Provide an initial copy of the NixOS channel so that the user
# doesn't need to run "nix-channel --update" first.
{ config, lib, pkgs, ... }:
with lib;
let
# We need a copy of the Nix expressions for Nixpkgs and NixOS on the
# CD. These are installed into the "nixos" channel of the root
# user, as expected by nixos-rebuild/nixos-install. FIXME: merge
# with make-channel.nix.
channelSources = pkgs.runCommand "nixos-${config.system.nixosVersion}"
{ }
''
mkdir -p $out
cp -prd ${pkgs.path} $out/nixos
chmod -R u+w $out/nixos
if [ ! -e $out/nixos/nixpkgs ]; then
ln -s . $out/nixos/nixpkgs
fi
rm -rf $out/nixos/.git
echo -n ${config.system.nixosVersionSuffix} > $out/nixos/.version-suffix
'';
in
{
# Provide the NixOS/Nixpkgs sources in /etc/nixos. This is required
# for nixos-install.
boot.postBootCommands = mkAfter
''
if ! [ -e /var/lib/nixos/did-channel-init ]; then
echo "unpacking the NixOS/Nixpkgs sources..."
mkdir -p /nix/var/nix/profiles/per-user/root
${config.nix.package}/bin/nix-env -p /nix/var/nix/profiles/per-user/root/channels \
-i ${channelSources} --quiet --option build-use-substitutes false
mkdir -m 0700 -p /root/.nix-defexpr
ln -s /nix/var/nix/profiles/per-user/root/channels /root/.nix-defexpr/channels
mkdir -m 0755 -p /var/lib/nixos
touch /var/lib/nixos/did-channel-init
fi
'';
}