[RF] Add a dependency on nlohmann_json.

RooFit multiprocess privately depends on nlohmann_json.
The res headers use it too, but since the dependency
is private, the tests cannot use it unless they explicitly
request nlohmann_json, too.

Author: hageboeck

roofit/multiprocess/test/CMakeLists.txt

@@ -12,7 +12,8 @@ ROOT_ADD_GTEST(test_RooFit_MultiProcess_ProcessManager test_ProcessManager.cxx L
 ROOT_ADD_GTEST(test_RooFit_MultiProcess_Messenger test_Messenger.cxx LIBRARIES RooFitMultiProcess)
 
 ROOT_ADD_GTEST(test_RooFit_MultiProcess_Queue test_Queue.cxx LIBRARIES RooFitMultiProcess)
-ROOT_ADD_GTEST(test_RooFit_MultiProcess_ProcessTimer test_ProcessTimer.cxx LIBRARIES RooFitMultiProcess)
+#nlohmann is only a private dependency of RF_MP, but this test includes a header in res/
+ROOT_ADD_GTEST(test_RooFit_MultiProcess_ProcessTimer test_ProcessTimer.cxx LIBRARIES RooFitMultiProcess nlohmann_json::nlohmann_json)
 ROOT_ADD_GTEST(test_RooFit_MultiProcess_HeatmapAnalyzer test_HeatmapAnalyzer.cxx LIBRARIES RooFitMultiProcess
   COPY_TO_BUILDDIR ${CMAKE_CURRENT_SOURCE_DIR}/test_logs/p_0.json
   COPY_TO_BUILDDIR ${CMAKE_CURRENT_SOURCE_DIR}/test_logs/p_1.json