anchor.diff:      src =
         if stdenv.system == "x86_64-linux" then
           fetchurl { # tested
  -          url = http://downloads.typesafe.com/scalaide-pack/4.4.1-vfinal-luna-211-20160504/scala-SDK-4.4.1-vfinal-2.11-linux.gtk.x86_64.tar.gz;
  +          url = https://downloads.typesafe.com/scalaide-pack/4.4.1-vfinal-luna-211-20160504/scala-SDK-4.4.1-vfinal-2.11-linux.gtk.x86_64.tar.gz;
             sha256  = "4c2d1ac68384e12a11a851cf0fc7757aea087eba69329b21d539382a65340d27";
           }
         else
           fetchurl { # untested
  -          url = http://downloads.typesafe.com/scalaide-pack/4.4.1-vfinal-luna-211-20160504/scala-SDK-4.4.1-vfinal-2.11-linux.gtk.x86.tar.gz;
  +          url = https://downloads.typesafe.com/scalaide-pack/4.4.1-vfinal-luna-211-20160504/scala-SDK-4.4.1-vfinal-2.11-linux.gtk.x86.tar.gz;
             sha256 = "35383cb09567187e14a30c15de9fd9aa0eef99e4bbb342396ce3acd11fb5cbac";
           };
     };
  
positive.code:     src =
        if stdenv.system == "x86_64-linux" then
          fetchurl {
            url = http://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/technology/epp/downloads/release/neon/R/eclipse-cpp-neon-R-linux-gtk-x86_64.tar.gz;
            sha256 = "09fqsgvbjfdqvn7z03crkii34z4bsb34y272q68ib8741bxk0i6m";
          }
        else if stdenv.system == "i686-linux" then
          fetchurl {
            url = http://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/technology/epp/downloads/release/neon/R/eclipse-cpp-neon-R-linux-gtk.tar.gz;
            sha256 = "0a12qmqq22v7sbmwn1hjv1zcrkmp64bf0ajmdjljhs9ac79mxn5h";
          }
        else throw "Unsupported system: ${stdenv.system}";
  
negative.code:     src =
        if stdenv.system == "x86_64-linux" then
          fetchurl {
            url = https://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/technology/epp/downloads/release/indigo/R/eclipse-cpp-indigo-incubation-linux-gtk-x86_64.tar.gz;
            sha256 = "14ppc9g9igzvj1pq7jl01vwhzb66nmzbl9wsdl1sf3xnwa9wnqk3";
          }
        else
          fetchurl {
            url = https://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/technology/epp/downloads/release/indigo/R/eclipse-cpp-indigo-incubation-linux-gtk.tar.gz;
            sha256 = "1cvg1vgyazrkinwzlvlf0dpl197p4784752srqybqylyj5psdi3b";
          };
    };
  