warning: unknown setting 'eval-cores'
warning: unknown setting 'lazy-trees'
these 2 derivations will be built:
  /nix/store/gj7l4ax8lfgy58zxc7aj3yrfcd6558y9-busker-shim-0.0.2.drv
  /nix/store/8i77qsp9ajc1l8dvsnbsrda1zmjnjfpl-busker-0.0.2.drv