diff -up ./CMakeLists.txt.2 ./CMakeLists.txt

--- ./CMakeLists.txt.2	2021-04-20 12:55:14.000000000 -0400

+++ ./CMakeLists.txt	2021-05-21 22:26:12.910191071 -0400

@@ -127,6 +127,22 @@ if(BUILD_TESTING)

       set(absl_gtest_src_dir ${ABSL_LOCAL_GOOGLETEST_DIR})

     endif()

     include(CMake/Googletest/DownloadGTest.cmake)

+  else()

+    # Set up gtest targets

+    find_library(GTEST_LIB gtest)

+    add_library(gtest UNKNOWN IMPORTED)

+    set_target_properties(gtest PROPERTIES IMPORTED_LOCATION ${GTEST_LIB})

+    find_library(GTEST_MAIN_LIB gtest_main)

+    add_library(gtest_main UNKNOWN IMPORTED)

+    set_target_properties(gtest_main PROPERTIES IMPORTED_LOCATION ${GTEST_MAIN_LIB} INTERFACE_LINK_LIBRARIES gtest)

+    

+    # Set up gmock targets

+    find_library(GMOCK_LIB gmock)

+    add_library(gmock UNKNOWN IMPORTED)

+    set_target_properties(gmock PROPERTIES IMPORTED_LOCATION ${GMOCK_LIB} INTERFACE_LINK_LIBRARIES gtest)

+    find_library(GMOCK_MAIN_LIB gmock_main)

+    add_library(gmock_main UNKNOWN IMPORTED)

+    set_target_properties(gmock_main PROPERTIES IMPORTED_LOCATION ${GMOCK_MAIN_LIB} INTERFACE_LINK_LIBRARIES "gmock;Threads::Threads")

   endif()

   check_target(gtest)