jansson: fix cmake import prefix (#434580)

pkgs/by-name/ja/jansson/package.nix

@@ -35,6 +35,12 @@ stdenv.mkDerivation (finalAttrs: {
     "-DJANSSON_BUILD_SHARED_LIBS=${if stdenv.hostPlatform.isStatic then "OFF" else "ON"}"
   ];
 
+  postFixup = ''
+    # Incorrectly references the dev output, libjansson.so is in out
+    substituteInPlace $dev/lib/cmake/jansson/janssonTargets-release.cmake \
+      --replace-fail "\''${_IMPORT_PREFIX}/lib" "$out/lib"
+  '';
+
   passthru = {
     tests.pkg-config = testers.hasPkgConfigModules { package = finalAttrs.finalPackage; };
     updateScript = nix-update-script { };