anchor.diff:      # "lift" packages like curl from the final stdenv for Linux to
       # all-packages.nix for that platform (meaning that it has a line
       # like curl = if stdenv ? curl then stdenv.curl else ...).
  -    // extraAttrs;
  -
  -in stdenv)
  +    // extraAttrs
  +); in stdenv-overridable
  
positive.code: 
    defaultBuildInputs = extraBuildInputs;
  
    # The stdenv that we are producing.
    stdenv =
      derivation (
      lib.optionalAttrs (allowedRequisites != null) {
        allowedRequisites = allowedRequisites
  
negative.code: let lib = import ../../../lib; stdenv-overridable = lib.makeOverridable (
  
  argsStdenv@{ name ? "stdenv", preHook ? "", initialPath
  
  , # If we don't have a C compiler, we might either have `cc = null` or `cc =
    # throw ...`, but if we do have a C compiler we should definiely have `cc !=
  