anchor.diff:      bash-completion  # (optional) dependency to install bash completion
       emacs  # (optional) to byte compile emacs code, also needed for tests
       ruby  # (optional) ruby bindings
  -    which dtach openssl bash  # test dependencies
  -  ]
  -  ++ optional stdenv.isDarwin fixDarwinDylibNames
  -  ++ optionals (!stdenv.isDarwin) [ gdb man ]; # test dependencies
  +  ];
   
     postPatch = ''
       patchShebangs configure
  -
  -    find test/ -type f -exec \
  -      sed -i \
  -        -e "1s|#!/usr/bin/env bash|#!${bash}/bin/bash|" \
  -        "{}" ";"
  +    patchShebangs test/
   
       for src in \
         util/crypto.c \
  
positive.code:   enableParallelBuilding = true;
    makeFlags = "V=1";
  
    preFixup = optionalString stdenv.isDarwin ''
      set -e
  
      die() {
        >&2 echo "$@"
        exit 1
      }
  
      prg="$out/bin/notmuch"
      lib="$(find "$out/lib" -name 'libnotmuch.?.dylib')"
  
      [[ -s "$prg" ]] || die "couldn't find notmuch binary"
      [[ -s "$lib" ]] || die "couldn't find libnotmuch"
  
      badname="$(otool -L "$prg" | awk '$1 ~ /libtalloc/ { print $1 }')"
      goodname="$(find "${talloc}/lib" -name 'libtalloc.*.*.*.dylib')"
  
      [[ -n "$badname" ]]  || die "couldn't find libtalloc reference in binary"
      [[ -n "$goodname" ]] || die "couldn't find libtalloc in nix store"
  
      echo "fixing libtalloc link in $lib"
      install_name_tool -change "$badname" "$goodname" "$lib"
  
      echo "fixing libtalloc link in $prg"
      install_name_tool -change "$badname" "$goodname" "$prg"
    '';
  
    preCheck = let
      test-database = fetchurl {
        url = "https://notmuchmail.org/releases/test-databases/database-v1.tar.xz";
  
negative.code:       substituteInPlace "$src" \
          --replace \"gpg\" \"${gnupg}/bin/gpg\"
      done
  
      substituteInPlace lib/Makefile.local \
        --replace '-install_name $(libdir)' "-install_name $out/lib"
    '';
  
    configureFlags = [ "--zshcompletiondir=$(out)/share/zsh/site-functions" ];
  