Index: tests/CMakeLists.txt
--- tests/CMakeLists.txt.orig
+++ tests/CMakeLists.txt
@@ -133,7 +133,12 @@ target_include_directories(Tests_run PUBLIC
     ${Python3_INCLUDE_DIRS}
     ${XercesC_INCLUDE_DIRS}
 )
+target_link_directories(Tests_run PUBLIC
+    "/usr/X11R6/lib"
+    "/usr/local/lib"
+)
 target_link_libraries(Tests_run
+    gtest
     gtest_main
     gmock_main
     ${Google_Tests_LIBS}
