anchor.diff:    # https://github.com/basvandijk/threads/issues/10
     threads = dontCheck super.threads;
   
  -  # https://github.com/NixOS/nixpkgs/issues/32138
  -  purescript = super.purescript.override {
  -    optparse-applicative = self.optparse-applicative_0_14_0_0;
  -  };
  -
     # Missing module.
     rematch = dontCheck super.rematch;            # https://github.com/tcrayford/rematch/issues/5
     rematch-text = dontCheck super.rematch-text;  # https://github.com/tcrayford/rematch/issues/6
  
positive.code:   # test suite requires git and does a bunch of git operations
    restless-git = dontCheck super.restless-git;
  
    # This tool needs the latest hackage-db version. Using the latest version of
    # optparse-applicative allows us to generate completions for fish and zsh.
    cabal2nix = super.cabal2nix.overrideScope (self: super: {
      hackage-db = self.hackage-db_2_0;
      optparse-applicative = self.optparse-applicative_0_14_0_0;
    });
  
    # Depends on broken fluid.
  
negative.code: 
    # The Hackage tarball is purposefully broken, because it's not intended to be, like, useful.
    # https://git-annex.branchable.com/bugs/bash_completion_file_is_missing_in_the_6.20160527_tarball_on_hackage/
    git-annex = (overrideCabal (drv: {
      src = pkgs.fetchgit {
        name = "git-annex-${drv.version}-src";
        url = "git://git-annex.branchable.com/";
  