these 2 derivations will be built:
  /nix/store/wmaf8yb468xslix8srpb2351rvhn9fn4-nix-source-patched-source.drv
  /nix/store/spdv4kfnha770370wsqjidsl678brmij-equal-contents-trivial-patch-does-not-change-source-contents.drv