anchor.diff:      description = "Eclipse platform";
       sources = {
         "x86_64-linux" = fetchurl {
  -          url = http://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/eclipse/downloads/drops4/R-4.6.1-201609071200/eclipse-SDK-4.6.1-linux-gtk-x86_64.tar.gz;
  +          url = https://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/eclipse/downloads/drops4/R-4.6.1-201609071200/eclipse-SDK-4.6.1-linux-gtk-x86_64.tar.gz;
             sha256 = "1mr7sj4whz23iwz5j6mbqd80a39177qv0r7b6cip7dji4n2agl8j";
           };
         "i686-linux" = fetchurl {
  -          url = http://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/eclipse/downloads/drops4/R-4.6.1-201609071200/eclipse-SDK-4.6.1-linux-gtk.tar.gz;
  +          url = https://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/eclipse/downloads/drops4/R-4.6.1-201609071200/eclipse-SDK-4.6.1-linux-gtk.tar.gz;
             sha256 = "0kgj0zpgzwx90q13c4mr8swf63azd56532ycxgq2rbs0d1qbl87j";
           };
       };
  
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";
          };
    };
  