Merge branch '22-adapt-to-cmakelists-txt-refactoring-in-core' of...

Merge branch '22-adapt-to-cmakelists-txt-refactoring-in-core' of https://gitlab.iri.upc.edu/mobile_robotics/wolf_projects/wolf_lib/plugins/apriltag into 22-adapt-to-cmakelists-txt-refactoring-in-core

test/CMakeLists.txt

 # Retrieve googletest from github & compile
 add_subdirectory(gtest)
 
+############# USE THIS TEST AS AN EXAMPLE #################
+#                                                         #
+# Create a specific test executable for gtest_example     #
+# wolf_add_gtest(gtest_example gtest_example.cpp)         #
+#                                                         #
+###########################################################
+
 wolf_add_gtest(gtest_feature_apriltag gtest_feature_apriltag.cpp)
 
 wolf_add_gtest(gtest_landmark_apriltag gtest_landmark_apriltag.cpp)

test/gtest/CMakeLists.txt

@@ -5,15 +5,7 @@ if(${CMAKE_VERSION} VERSION_LESS "3.11.0")
   include(ExternalProject)
 
   set(GTEST_FORCE_SHARED_CRT ON)
-  set(GTEST_DISABLE_PTHREADS OFF)
-
-  # For some reason I need to disable PTHREADS
-  # with g++ (Ubuntu 4.9.3-8ubuntu2~14.04) 4.9.3
-  # This is a known issue for MinGW :
-  # https://github.com/google/shaderc/pull/174
-  #if(MINGW)
-  #    set(GTEST_DISABLE_PTHREADS ON)
-  #endif()
+  set(GTEST_DISABLE_PTHREADS ON) # without this in ubuntu 18.04 we get linking errors
 
   # Download GoogleTest
   ExternalProject_Add(googletest
@@ -63,6 +55,7 @@ else()
     GIT_REPOSITORY https://github.com/google/googletest.git 
     GIT_TAG main)
 
+  SET(INSTALL_GTEST OFF) # Disable installation of googletest
   FetchContent_MakeAvailable(googletest)
     
 endif()