anchor.diff:      ++ optional withDebug   [ "--debug" ];
   
     postConfigure = ''
  -    ./configure python  --module=python    --config=${python}/bin/python-config  --lib-path=${python}/lib
  -    ./configure php     --module=php71     --config=${php71.dev}/bin/php-config  --lib-path=${php71}/lib
  -    ./configure php     --module=php72     --config=${php72.dev}/bin/php-config  --lib-path=${php72}/lib
  -    ./configure php     --module=php73     --config=${php73.dev}/bin/php-config  --lib-path=${php73}/lib
  -    ./configure perl    --module=perl      --perl=${perl}/bin/perl
  -    ./configure perl    --module=perl529   --perl=${perldevel}/bin/perl
  -    ./configure ruby    --module=ruby23    --ruby=${ruby_2_3}/bin/ruby
  -    ./configure ruby    --module=ruby24    --ruby=${ruby_2_4}/bin/ruby
  -    ./configure ruby    --module=ruby      --ruby=${ruby}/bin/ruby
  +    ${optionalString withPython     "./configure python  --module=python    --config=${python}/bin/python-config  --lib-path=${python}/lib"}
  +    ${optionalString withPHP71      "./configure php     --module=php71     --config=${php71.dev}/bin/php-config  --lib-path=${php71}/lib"}
  +    ${optionalString withPHP72      "./configure php     --module=php72     --config=${php72.dev}/bin/php-config  --lib-path=${php72}/lib"}
  +    ${optionalString withPHP73      "./configure php     --module=php73     --config=${php73.dev}/bin/php-config  --lib-path=${php73}/lib"}
  +    ${optionalString withPerl       "./configure perl    --module=perl      --perl=${perl}/bin/perl"}
  +    ${optionalString withPerldevel  "./configure perl    --module=perl529   --perl=${perldevel}/bin/perl"}
  +    ${optionalString withRuby_2_3   "./configure ruby    --module=ruby23    --ruby=${ruby_2_3}/bin/ruby"}
  +    ${optionalString withRuby_2_4   "./configure ruby    --module=ruby24    --ruby=${ruby_2_4}/bin/ruby"}
  +    ${optionalString withRuby       "./configure ruby    --module=ruby      --ruby=${ruby}/bin/ruby"}
     '';
   
     meta = {
  
positive.code: { stdenv, fetchurl
  , which
  , python
  , php71
  , php72
  , php73
  , perl
  , perldevel
  , ruby_2_3
  , ruby_2_4
  , ruby
  , withSSL ? true, openssl ? null
  , withIPv6 ? true
  , withDebug ? false
  
negative.code: with stdenv.lib;
  
  stdenv.mkDerivation rec {
    version = "1.7";
    name = "unit-${version}";
  
    src = fetchFromGitHub {
      owner = "nginx";
      repo = "unit";
      rev = "${version}";
      sha256 = "1klwricr0mxhw5wka35vnl919821vcvaf5w3ixvkbxaisml19qq4";
    };
  
    nativeBuildInputs = [ which ];
  
    buildInputs = [ ]
      ++ optional withPython python
      ++ optional withPHP71 php71
      ++ optional withPHP72 php72
      ++ optional withPHP73 php73
      ++ optional withPerl perl
      ++ optional withPerldevel perldevel
      ++ optional withRuby_2_3 ruby_2_3
      ++ optional withRuby_2_4 ruby_2_4
      ++ optional withRuby ruby
      ++ optional withSSL openssl;
  
    configureFlags = [
      "--control=unix:/run/control.unit.sock"
  