anchor.diff: -{ stdenv, fetchFromGitHub, php, flex }:
  +{ bison
  +, fetchFromGitHub
  +, flex
  +, php
  +, stdenv
  +}:
   
   # Make a custom wrapper. If `wrapProgram` is used, arcanist thinks .arc-wrapped is being
   # invoked and complains about it being an unknown toolset. We could use `makeWrapper`, but
   # then we’d need to still craft a script that does the `php libexec/arcanist/bin/...` dance
   # anyway... So just do everything at once.
   let makeArcWrapper = toolset: ''
  -    cat << WRAPPER > $out/bin/${toolset}
  -    #!$shell -e
  -    export PATH='${php}/bin/'\''${PATH:+':'}\$PATH
  -    exec ${php}/bin/php $out/libexec/arcanist/bin/${toolset} "\$@"
  -    WRAPPER
  -    chmod +x $out/bin/${toolset}
  +  cat << WRAPPER > $out/bin/${toolset}
  +  #!$shell -e
  +  export PATH='${php}/bin/'\''${PATH:+':'}\$PATH
  +  exec ${php}/bin/php $out/libexec/arcanist/bin/${toolset} "\$@"
  +  WRAPPER
  +  chmod +x $out/bin/${toolset}
   '';
   
   in
  -
   stdenv.mkDerivation {
     pname = "arcanist";
     version = "20200711";
  
positive.code:   '';
  
    buildPhase = ''
      make xhpast -C support/xhpast
    '';
  
    installPhase = ''
      mkdir -p $out/bin $out/libexec
      make install -C support/xhpast
      cp -R $src $out/libexec/arcanist
  
      ${makeArcWrapper "arc"}
      ${makeArcWrapper "phage"}
  
negative.code:     rev = "2565cc7b4d1dbce6bc7a5b3c4e72ae94be4712fe";
      sha256 = "0jiv4aj4m5750dqw9r8hizjkwiyxk4cg4grkr63sllsa2dpiibxw";
    };
    buildInputs = [ bison flex php ];
  
    postPatch = stdenv.lib.optionalString stdenv.isAarch64 ''
      substituteInPlace support/xhpast/Makefile \
  