anchor.diff:  
     ### Eclipse SDK
   
  -  eclipse-sdk = eclipse-sdk-49; # always point to latest
  -
  -  eclipse-sdk-47 = buildEclipse {
  -    name = "eclipse-sdk-4.7.3a";
  -    description = "Eclipse Oxygen Classic";
  -    sources = {
  -      "x86_64-linux" = fetchurl {
  -          url = https://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/eclipse/downloads/drops4/R-4.7.3a-201803300640/eclipse-SDK-4.7.3a-linux-gtk-x86_64.tar.gz;
  -          sha512 = "d77e42aca16d26526cef32e363d038258bb8a4616d9dbe6e76dd3656dc2217369436390a82555bde4566bbbdb631813bbaca08602f7bb885cb30e8a26a14873f";
  -        };
  -      "i686-linux" = fetchurl {
  -          url = https://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/eclipse/downloads/drops4/R-4.7.3a-201803300640/eclipse-SDK-4.7.3a-linux-gtk.tar.gz;
  -          sha512 = "b0b936fd4142ae86ec5c30535cd5e4caf6fe313d814ae5b16f300635e4163a79b748b1eee11792a135114f2265678a74821ec80c2bfd69872769b6d0ccbcde3a";
  -        };
  -    };
  -  };
  -
  -  eclipse-sdk-48 = buildEclipse {
  -    name = "eclipse-sdk-4.8";
  -    description = "Eclipse Photon Classic";
  -    sources = {
  -      "x86_64-linux" = fetchurl {
  -          url = https://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/eclipse/downloads/drops4/R-4.8-201806110500/eclipse-SDK-4.8-linux-gtk-x86_64.tar.gz;
  -          sha512 = "357ea9e7f426c68ced693f1c7b76eae23f9e3c7893de1f12d17994ec17b447896b5daa7292d5fbf6d9c4e5b7fd637ca5b2a6ba8ce40a2a7c2fe06f2124d31b75";
  -        };
  -      "i686-linux" = fetchurl {
  -          url = https://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/eclipse/downloads/drops4/R-4.8-201806110500/eclipse-SDK-4.8-linux-gtk.tar.gz;
  -          sha512 = "c7cae7baa3978d48477090bb9941e85b4c7484021ece9c5c77a7e859e57e5c1f13556262f92b561cfb11f828b934bad7a6018be7b8fd9454e3991e8d5cae9917";
  -        };
  -    };
  -  };
  -
  -  eclipse-sdk-49 = buildEclipse {
  +  eclipse-sdk = buildEclipse {
       name = "eclipse-sdk-4.9";
       description = "Eclipse 2018-09 Classic";
       sources = {
  
positive.code:     };
    };
  
    eclipse-sdk-37 = buildEclipse {
      name = "eclipse-sdk-3.7";
      description = "Eclipse Classic";
      sources = {
        "x86_64-linux" = fetchurl {
            url = https://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/eclipse/downloads/drops/R-3.7.2-201202080800/eclipse-SDK-3.7.2-linux-gtk-x86_64.tar.gz;
            sha256 = "0nf4nv7awhp1k8b1hjb7chpjyjrqnyszsjbc4dlk9phpjv3j4wg5";
          };
        "i686-linux" = fetchurl {
            url = https://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/eclipse/downloads/drops/R-3.7.2-201202080800/eclipse-SDK-3.7.2-linux-gtk.tar.gz;
            sha256 = "1isn7i45l9kyn2yx6vm88jl1gnxph8ynank0aaa218cg8kdygk7j";
          };
      };
    };
    eclipse_sdk_37 = eclipse-sdk-37; # backward compatibility, added 2016-01-30
  
    ### Eclipse Java
  
    eclipse-java = eclipse-java-49;
  
    eclipse-java-49 = buildEclipse {
      name = "eclipse-java-4.9.0";
      description = "Eclipse IDE for Java Developers";
      src =
  
negative.code:         };
    };
  
    ### Eclipse Platform
  
    eclipse-platform = buildEclipse {
      name = "eclipse-platform-4.9";
      description = "Eclipse Platform 2018-09";
      sources = {
  