rocfft: restructure to allow hydra caching

pkgs/development/libraries/rocfft/default.nix

@@ -2,6 +2,7 @@
 , stdenv
 , fetchFromGitHub
 , rocmUpdateScript
+, runCommand
 , cmake
 , rocm-cmake
 , hip
@@ -16,7 +17,8 @@
 , buildBenchmarks ? false
 }:
 
-stdenv.mkDerivation (finalAttrs: {
+let
+  rocfft = stdenv.mkDerivation (finalAttrs: {
     pname = "rocfft";
     version = "5.4.2";
 
@@ -104,6 +106,50 @@ stdenv.mkDerivation (finalAttrs: {
       license = with licenses; [ mit ];
       maintainers = teams.rocm.members;
       broken = versions.minor finalAttrs.version != versions.minor hip.version;
-    hydraPlatforms = [ ]; # rocFFT produces an extremely large output
     };
-})
+  });
+
+  rocfft-zero = runCommand "rocfft-zero" { preferLocalBuild = true; } ''
+    mkdir -p $out
+    cp -a ${rocfft}/lib/librocfft-device-0* $out
+  '';
+
+  rocfft-one = runCommand "rocfft-one" { preferLocalBuild = true; } ''
+    mkdir -p $out
+    cp -a ${rocfft}/lib/librocfft-device-1* $out
+  '';
+
+  rocfft-two = runCommand "rocfft-two" { preferLocalBuild = true; } ''
+    mkdir -p $out
+    cp -a ${rocfft}/lib/librocfft-device-2* $out
+  '';
+
+  rocfft-three = runCommand "rocfft-three" { preferLocalBuild = true; } ''
+    mkdir -p $out
+    cp -a ${rocfft}/lib/librocfft-device-3* $out
+  '';
+in stdenv.mkDerivation {
+  inherit (rocfft) pname version outputs src passthru meta;
+
+  dontUnpack = true;
+  dontConfigure = true;
+  dontBuild = true;
+
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p $out/lib
+
+    for path in ${rocfft-zero} ${rocfft-one} ${rocfft-two} ${rocfft-three}; do
+      cp -as $path/* $out/lib
+    done
+
+    cp -an ${rocfft}/* $out
+  '' + lib.optionalString buildTests ''
+    cp -a ${rocfft.test} $test
+  '' + lib.optionalString buildBenchmarks ''
+    cp -a ${rocfft.benchmark} $benchmark
+  '' + ''
+    runHook postInstall
+  '';
+}