anchor.diff:        odbc    = "1g1z6pdn76dp440fh49pm8ijfgjazx4cvxdi665fsr62h62xkvch";
       };
       x86_64-darwin = {
  -      basic   = "fac3cdaaee7526f6c50ff167edb4ba7ab68efb763de24f65f63fb48cc1ba44c0";
  -      sdk     = "98e6d797f1ce11e59b042b232f62380cec29ec7d5387b88a9e074b741c13e63a";
  -      sqlplus = "02e66dc52398fced75e7efcb6b4372afcf617f7d88344fb7f0f4bb2bed371f3b";
  -      odbc    = "5d0cdd7f9dd2e27affbc9b36ef9fc48e329713ecd36905fdd089366e365ae8a2";
  +      basic   = "f4335c1d53e8188a3a8cdfb97494ff87c4d0f481309284cf086dc64080a60abd";
  +      sdk     = "b46b4b87af593f7cfe447cfb903d1ae5073cec34049143ad8cdc9f3e78b23b27";
  +      sqlplus = "f7565c3cbf898b0a7953fbb0017c5edd9d11d1863781588b7caf3a69937a2e9e";
  +      odbc    = "f91da40684abaa866aa059eb26b1322f2d527670a1937d678404c991eadeb725";
       };
     }.${stdenv.hostPlatform.system} or throwSystem;
   
     # rels per component and architecture, optional
     rels = {
  -    x86_64-darwin = {
  -      sdk = "2";
  -    };
     }.${stdenv.hostPlatform.system} or {};
   
     # convert platform to oracle architecture names
  
positive.code:     x86_64-darwin = "macos.x64";
    }.${stdenv.hostPlatform.system} or throwSystem;
  
    # calculate the filename of a single zip file
    srcFilename = component: arch: version: rel:
      "instantclient-${component}-${arch}-${version}" +
      (optionalString (rel != "") "-${rel}") +
      (optionalString (arch == "linux.x64") "dbru") + # ¯\_(ツ)_/¯
      ".zip";
  
    # fetcher for the clickthrough artifacts (requiring manual download)
    fetchClickThrough =  srcFilename: hash: (requireFile {
      name = srcFilename;
      url = "https://www.oracle.com/database/technologies/instant-client/downloads.html";
      sha256 = hash;
    });
  
    # fetcher for the non clickthrough artifacts
    fetchSimple = srcFilename: hash: fetchurl {
      url = "https://download.oracle.com/otn_software/linux/instantclient/193000/${srcFilename}";
      sha256 = hash;
    };
  
    # pick the appropriate fetcher depending on the platform
    fetcher = if stdenv.hostPlatform.system == "x86_64-linux" then fetchSimple else fetchClickThrough;
  
    # assemble srcs
    srcs = map (component:
  
negative.code: { stdenv
  , fetchurl
  , autoPatchelfHook
  , fixDarwinDylibNames
  , unzip
  