util/liveiso: Ensure compatible NixOS channel is used

Config options and package names might change from channel to channel.
Thus, don't let nix-build depend on the locally configured NixOS
channel, but instead let `nixpkgs` point to a specific channel to ensure
that always a compatible channel is used.

For now, let `nixpkgs` point to NixOS 21.11, which is currently the
latest stable release. This needs to be updated after a new release.

Change-Id: Ia77c34f93f0e2c3d351ae229830adfce75a56ae4
Signed-off-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60373
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>

0 files changed, 0 insertions, 0 deletions