anchor.diff:      };
       llbuild = fetchSwiftRelease {
         repo = "swift-llbuild";
  -      sha256 = "0d7sj5a9b5c1ry2209cpccic5radf9s48sp1lahqzmd1pdx3n7pi";
  -    };
  -    argumentParser = fetchFromGitHub {
  -      owner = "apple";
  -      repo = "swift-argument-parser";
  -      rev = swiftArgumentParserVersion;
  -      sha256 = "15vv7hnffa84142q97dwjcn196p2bg8nfh89d6nnix0i681n1qfd";
  -      name = "swift-argument-parser-${swiftArgumentParserVersion}";
  +      sha256 = "1xmiv7yp9r9iscx3fc3zdp25mriz134k9ny2rchxzi4kifz8h0zc";
       };
       driver = fetchSwiftRelease {
         repo = "swift-driver";
  -      sha256 = "1j08273haqv7786rkwsmw7g103glfwy1d2807490id9lagq3r66z";
  +      sha256 = "1pb7fidgdqxzragqkillkv03vdilrwmcx6x2r4czqvdqj37gy6b6";
       };
       toolsSupportCore = fetchSwiftRelease {
         repo = "swift-tools-support-core";
  -      sha256 = "07gm28ki4px7xzrplvk9nd1pp5r9nyi87l21i0rcbb3r6wrikxb4";
  +      sha256 = "0a63193nycir4lffvmb3ky8cfly5kdr2libki2gx4fn6fxmb3a2f";
       };
       swiftpm = fetchSwiftRelease {
         repo = "swift-package-manager";
  -      sha256 = "05linnzlidxamzl3723zhyrfm24pk2cf1x66a3nk0cxgnajw0vzx";
  +      sha256 = "0hdjvb2asfi6h3x9bjssxkc3bgjn3idlmyga3dl3lscfq88hjxr9";
       };
       syntax = fetchSwiftRelease {
         repo = "swift-syntax";
  -      sha256 = "1y9agx9bg037xjhkwc28xm28kjyqydgv21s4ijgy5l51yg1g0daj";
  -    };
  -    # TODO: possibly re-add stress-tester.
  +      sha256 = "0kdgh9a8n28yh12hj8lbz2j66ag83l0lcfyfdg7zdr614zs6i3p1";
  +    };
       corelibsXctest = fetchSwiftRelease {
         repo = "swift-corelibs-xctest";
  -      sha256 = "00c68580yr12yxshl0hxyhp8psm15fls3c7iqp52hignyl4v745r";
  +      sha256 = "12fp3xzsqwcrmyc55h91d3dm64wn3wln47x2fl7sj0s8cn7q12b3";
       };
       corelibsFoundation = fetchSwiftRelease {
         repo = "swift-corelibs-foundation";
  -      sha256 = "1jyadm2lm7hhik8n8wacfiffpdwqsgnilwmcw22qris5s2drj499";
  +      sha256 = "1f7qcdx8597gwqa9pwl38d31w6w4d84c5hadj4ycj99msrm2f32x";
       };
       corelibsLibdispatch = fetchSwiftRelease {
         repo = "swift-corelibs-libdispatch";
  -      sha256 = "1s46c0hrxi42r43ff5f1pq2imb3hs05adfpwfxkilgqyb5svafsp";
  +      sha256 = "1bim5x9z9bqfgs6gdm4nlz1zrwl2x7xh4dn6i5md9ygsplr4ibzf";
         fetchSubmodules = true;
       };
  -    # TODO: possibly re-add integration-tests.
  -    # Linux does not support Xcode playgrounds.
  -    # We provide our own ninja.
  -    # We provider our own icu.
  +    indexstoreDb = fetchSwiftRelease {
  +      repo = "indexstore-db";
  +      sha256 = "1l1xlzf5kx7x80kf4b7r36glv0jc64d08d1688kmzjq1cfgn6gm2";
  +    };
  +    sourcekitLsp = fetchSwiftRelease {
  +      repo = "sourcekit-lsp";
  +      sha256 = "00fcmd7x5v62n6ajsc0dmzwz6nzy2p72mcs9w6p90adcx7pffqkn";
  +    };
  +    llvmProject = fetchSwiftRelease {
  +      repo = "llvm-project";
  +      sha256 = "1gvqps5f9jh6lbhcjh1fyzp3bc0h9chbljzaspcrdi2qp878prlx";
  +    };
  +
  +    # Projects that have their own versions during each release
  +
  +    argumentParser = fetchAppleRepo {
  +      repo = "swift-argument-parser";
  +      rev = "${versions.argumentParser}";
  +      sha256 = "1jkq72fphxzsnynjxk72azp0iz5r2ji7adxrz6w1y2a19pgjdqrp";
  +    };
  +    format = fetchAppleRepo {
  +      repo = "swift-format";
  +      rev = "${versions.format}";
  +      sha256 = "1hg888ps3fk23q2zf6djkvxyk6zndqvwypmy0s800hmnyf0hzgv4";
  +    };
  +    crypto = fetchAppleRepo {
  +      repo = "swift-crypto";
  +      rev = "${versions.crypto}";
  +      sha256 = "0918pj3x3wgli3bnrjbvpzck2n6qz5n6f4yc5kljky45wd15f34g";
  +    };
       yams = fetchFromGitHub {
         owner = "jpsim";
         repo = "Yams";
  -      rev = yamsVersion;
  -      sha256 = "13md54y7lalrpynrw1s0w5yw6rrjpw46fml9dsk2m3ph1bnlrqrq";
  -      name = "Yams-${yamsVersion}";
  -    };
  -    # We provide our own CMake.
  -    indexstoreDb = fetchSwiftRelease {
  -      repo = "indexstore-db";
  -      sha256 = "1ap3hiq2jd3cn10d8d674xysq27by878mvq087a80681r8cdivn3";
  -    };
  -    sourcekitLsp = fetchSwiftRelease {
  -      repo = "sourcekit-lsp";
  -      sha256 = "02m9va0lsn2hnwkmgrbgj452sbyaswwmq14lqvxgnb7gssajv4gc";
  -    };
  -    format = fetchFromGitHub {
  -      owner = "apple";
  -      repo = "swift-format";
  -      rev = swiftFormatVersion;
  -      sha256 = "0skmmggsh31f3rnqcrx43178bc7scrjihibnwn68axagasgbqn4k";
  -      name = "swift-format-${swiftFormatVersion}-src";
  -    };
  -    llvmProject = fetchSwiftRelease {
  -      repo = "llvm-project";
  -      sha256 = "166hd9d2i55zj70xjb1qmbblbfyk8hdb2qv974i07j6cvynn30lm";
  +      rev = versions.yams;
  +      sha256 = "1nk9b7l6m3wwjkl81npl2l1iwpsxaxb9za53jpwwsbbi1h1h4fbi";
  +      name = "Yams-${versions.yams}-src";
       };
     };
   
  
positive.code:   meta = with lib; {
      description = "The Swift Programming Language";
      homepage = "https://github.com/apple/swift";
      maintainers = with maintainers; [ dtzWill trepetti ];
      license = licenses.asl20;
      # Swift doesn't support 32-bit Linux, unknown on other platforms.
      platforms = platforms.linux;
  
negative.code:     cp -r ${sources.toolsSupportCore} swift-tools-support-core
      cp -r ${sources.swiftpm} swiftpm
      cp -r ${sources.syntax} swift-syntax
      cp -r ${sources.corelibsXctest} swift-corelibs-xctest
      cp -r ${sources.corelibsFoundation} swift-corelibs-foundation
      cp -r ${sources.corelibsLibdispatch} swift-corelibs-libdispatch
      cp -r ${sources.yams} yams
      cp -r ${sources.indexstoreDb} indexstore-db
      cp -r ${sources.sourcekitLsp} sourcekit-lsp
      cp -r ${sources.format} swift-format
      cp -r ${sources.crypto} swift-crypto
      cp -r ${sources.llvmProject} llvm-project
  
      chmod -R u+w .
  