flatbuffers: remove version 1.12

It has not been updated upstream for over two years, and it is starting
to become time consuming to maintain.

pkgs/development/libraries/flatbuffers/1.12.nix

@@ -1,26 +0,0 @@
-{ callPackage, fetchpatch, lib, stdenv }:
-
-callPackage ./generic.nix {
-  version = "1.12.0";
-  sha256 = "0f7xd66vc1lzjbn7jzd5kyqrgxpsfxi4zc7iymhb5xrwyxipjl1g";
-
-  patches = [
-    (fetchpatch {
-      # Fixed a compilation error with GCC 10.0 to 11.0. June 1, 2020.
-      # Should be included in the next release after 1.12.0
-      url = "https://github.com/google/flatbuffers/commit/988164f6e1675bbea9c852e2d6001baf4d1fcf59.patch";
-      sha256 = "0d8c2bywqmkhdi0a41cry85wy4j58pl0vd6h5xpfqm3fr8w0mi9s";
-      excludes = [ "src/idl_gen_cpp.cpp" ];
-    })
-    (fetchpatch {
-      # Fixed a compilation error with GCC 10.0 to 11.0. July 6, 2020.
-      # Should be included in the next release after 1.12.0
-      url = "https://github.com/google/flatbuffers/pull/6020/commits/44c7a4cf439b0a298720b5a448bcc243a882b0c9.patch";
-      sha256 = "126xwkvnlc4ignjhxv9jygfd9j6kr1jx39hyk0ddpcmvzfqsccf4";
-    })
-  ];
-
-  preConfigure = lib.optionalString stdenv.buildPlatform.isDarwin ''
-    rm BUILD
-  '';
-}

pkgs/development/libraries/flatbuffers/2.0.nix

@@ -1,16 +0,0 @@
-{ callPackage, fetchpatch }:
-
-callPackage ./generic.nix {
-  version = "2.0.0";
-  sha256 = "1zbf6bdpps8369r1ql00irxrp58jnalycc8jcapb8iqg654vlfz8";
-
-  patches = [
-    # Pull patch pending upstream inclustion for gcc-12 support:
-    #  https://github.com/google/flatbuffers/pull/6946
-    (fetchpatch {
-      name = "gcc-12.patch";
-      url = "https://github.com/google/flatbuffers/commit/17d9f0c4cf47a9575b4f43a2ac33eb35ba7f9e3e.patch";
-      sha256 = "0sksk47hi7camja9ppnjr88jfdgj0nxqxy8976qs1nx73zkgbpf9";
-    })
-  ];
-}

pkgs/development/libraries/flatbuffers/default.nix

@@ -1,25 +1,30 @@
 { lib
 , stdenv
 , fetchFromGitHub
+, fetchpatch
 , cmake
-, version
-, sha256
-, patches ? [ ]
-, preConfigure ? null
 }:
 
 stdenv.mkDerivation rec {
   pname = "flatbuffers";
-  inherit version;
+  version = "2.0.0";
 
   src = fetchFromGitHub {
     owner = "google";
     repo = "flatbuffers";
     rev = "v${version}";
-    inherit sha256;
+    sha256 = "1zbf6bdpps8369r1ql00irxrp58jnalycc8jcapb8iqg654vlfz8";
   };
 
-  inherit patches preConfigure;
+  patches = [
+    # Pull patch pending upstream inclustion for gcc-12 support:
+    # https://github.com/google/flatbuffers/pull/6946
+    (fetchpatch {
+      name = "gcc-12.patch";
+      url = "https://github.com/google/flatbuffers/commit/17d9f0c4cf47a9575b4f43a2ac33eb35ba7f9e3e.patch";
+      sha256 = "0sksk47hi7camja9ppnjr88jfdgj0nxqxy8976qs1nx73zkgbpf9";
+    })
+  ];
 
   nativeBuildInputs = [ cmake ];
 

pkgs/top-level/aliases.nix

@@ -403,6 +403,8 @@ mapAliases ({
   flashplayer-standalone = throw "flashplayer-standalone has been removed as Adobe Flash Player is now deprecated"; # Added 2021-02-07
   flashplayer = throw "flashplayer has been removed as Adobe Flash Player is now deprecated"; # Added 2021-02-07
   flashtool = throw "flashtool was removed from nixpkgs, because the download is down for copyright reasons and the site looks very fishy"; # Added 2021-06-31
+  flatbuffers_1_12 = throw "FlatBuffers version 1.12 has been removed, because upstream no longer maintains it"; # Added 2022-05-12
+  flatbuffers_2_0 = flatbuffers; # Added 2022-05-12
   flink_1_5 = throw "flink_1_5 was removed, use flink instead"; # Added 2021-01-25
   flutter-beta = throw "Non-stable versions of Flutter have been removed. You can use flutterPackages.mkFlutter to generate a package for other Flutter versions"; # Added 2020-01-15
   flutter-dev = throw "Non-stable versions of Flutter have been removed. You can use flutterPackages.mkFlutter to generate a package for other Flutter versions"; # Added 2020-01-15

pkgs/top-level/all-packages.nix

@@ -20135,9 +20135,7 @@ with pkgs;
 
   protozero = callPackage ../development/libraries/protozero { };
 
-  flatbuffers = flatbuffers_2_0;
-  flatbuffers_2_0 = callPackage ../development/libraries/flatbuffers/2.0.nix { };
-  flatbuffers_1_12 = callPackage ../development/libraries/flatbuffers/1.12.nix { };
+  flatbuffers = callPackage ../development/libraries/flatbuffers { };
 
   nanopb = callPackage ../development/libraries/nanopb { };