these 2 derivations will be built:
  /nix/store/7w6xf8lzhln12jfsa4iwam9xmahx2nyq-nix-bindings-expr-deps-0.2.1.drv
  /nix/store/3b5snqrx0px1rkqidp0g1lnxkffzr01k-nix-bindings-expr-0.2.1.drv