ONNX will build googletest from a Git checkout.  Patch CMake to use our
googletest package and enable tests by default.

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0aa9fda2..a573170c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,7 +22,7 @@ option(BUILD_ONNX_PYTHON "Build Python binaries" OFF)
 option(ONNX_GEN_PB_TYPE_STUBS "Generate protobuf python type stubs" ON)
 option(ONNX_WERROR "Build with Werror" OFF)
 option(ONNX_COVERAGE "Build with coverage instrumentation" OFF)
-option(ONNX_BUILD_TESTS "Build ONNX C++ APIs Tests" OFF)
+option(ONNX_BUILD_TESTS "Build ONNX C++ APIs Tests" ON)
 option(ONNX_USE_LITE_PROTO "Use lite protobuf instead of full." OFF)
 option(ONNXIFI_ENABLE_EXT "Enable onnxifi extensions." OFF)
 if(NOT DEFINED ONNX_ML)
@@ -82,8 +82,10 @@ if(CMAKE_SYSTEM_NAME STREQUAL "AIX")
 endif()

 if(ONNX_BUILD_TESTS)
-  list(APPEND CMAKE_MODULE_PATH ${ONNX_ROOT}/cmake/external)
-  include(googletest)
+  find_package(GTest REQUIRED)
+  if(NOT GTest_FOUND)
+    message(FATAL_ERROR "cannot find googletest")
+  endif()
 endif()

 if((ONNX_USE_LITE_PROTO AND TARGET protobuf::libprotobuf-lite) OR ((NOT ONNX_USE_LITE_PROTO) AND TARGET protobuf::libprotobuf))
diff --git a/cmake/unittest.cmake b/cmake/unittest.cmake
index e29a93ff..ae146390 100644
--- a/cmake/unittest.cmake
+++ b/cmake/unittest.cmake
@@ -6,8 +6,8 @@ include(${ONNX_ROOT}/cmake/Utils.cmake)

 find_package(Threads)

-set(${UT_NAME}_libs ${googletest_STATIC_LIBRARIES})
-set(${ONNXIFI_TEST_DRIVER}_libs ${googletest_STATIC_LIBRARIES})
+set(${UT_NAME}_libs ${GTEST_LIBRARIES})
+set(${ONNXIFI_TEST_DRIVER}_libs ${GTEST_LIBRARIES})

 list(APPEND ${UT_NAME}_libs onnx)
 list(APPEND ${UT_NAME}_libs onnx_proto)
@@ -31,10 +31,10 @@ function(AddTest)
   list(REMOVE_DUPLICATES _UT_SOURCES)

   add_executable(${_UT_TARGET} ${_UT_SOURCES})
-  add_dependencies(${_UT_TARGET} onnx onnx_proto googletest)
+  add_dependencies(${_UT_TARGET} onnx onnx_proto)

   target_include_directories(${_UT_TARGET}
-                             PUBLIC ${googletest_INCLUDE_DIRS}
+                             PUBLIC ${GTEST_INCLUDE_DIRS}
                                     ${ONNX_INCLUDE_DIRS}
                                     ${PROTOBUF_INCLUDE_DIRS}
                                     ${ONNX_ROOT}
r'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/system.scm?id=9584b1daa687d1212550841d1c5f62e7ffa44ffc&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-03-03 17:55:31 +0100'>2023-03-03</span></td><td><a href='/guix/commit/gnu/system.scm?id=cb00e600ffe7ec493464788dd16308b7b8e87d20'>services: base: Deprecate 'host-name-service' procedure.</a><span class='msg-avail'>...</span></td><td>Bruno Victal</td></tr>
<tr><td><span title='2023-02-23 16:31:36 +0100'>2023-02-23</span></td><td><a href='/guix/commit/gnu/system.scm?id=c742615b76a3d992b2d7d3e8db4cf5115991f16c'>system: Do not export local-host-entries.</a><span class='msg-avail'>...</span></td><td>Bruno Victal</td></tr>
<tr><td><span title='2023-02-09 01:07:47 +0100'>2023-02-09</span></td><td><a href='/guix/commit/gnu/system.scm?id=802ea1f3a43e5fb8d0b8bd2882954d8a6e49cde6'>system: Deprecate hosts-file.</a><span class='msg-avail'>...</span></td><td>Bruno Victal</td></tr>
<tr><td><span title='2023-01-05 15:00:27 +0100'>2023-01-05</span></td><td><a href='/guix/commit/gnu/system.scm?id=086df6ef213d44d4b75c263033552eef6b2bd868'>system: Define default 'PS1' in /etc/bashrc rather than ~/.bashrc.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-12-05 11:21:18 -0500'>2022-12-05</span></td><td><a href='/guix/commit/gnu/system.scm?id=bb689fda925430d99e911a7613085fc24300dca3'>system: Add e2fsprogs to %base-packages-utils.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-12-05 10:38:41 -0500'>2022-12-05</span></td><td><a href='/guix/commit/gnu/system.scm?id=1603c78aa4657d9f6e3b7cf1daace40043ff3e9a'>system: Rename and move %base-packages-disk-utilities.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-10-23 17:03:09 -0700'>2022-10-23</span></td><td><a href='/guix/commit/gnu/system.scm?id=d3e982dccbd8ec7e00a2ab3efa04bef8f1c16b9e'>gnu: Fix typos.</a><span class='msg-avail'>...</span></td><td>Vagrant Cascadian</td></tr>
<tr><td><span title='2022-10-23 15:56:18 +0200'>2022-10-23</span></td><td><a href='/guix/commit/gnu/system.scm?id=3fb3bd3da530a5f82a169b1fa451474f9d90c3b6'>system: hurd: Boot with the statically-linked 'exec' server.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-10-11 11:29:03 +0000'>2022-10-11</span></td><td><a href='/guix/commit/gnu/system.scm?id=f78cfcd7d3f1f76a5c09c21d76b14983d8428c4d'>system: operating-system: Make the timezone field default to Etc/UTC.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-09-28 19:45:38 -0400'>2022-09-28</span></td><td><a href='/guix/commit/gnu/system.scm?id=45eac6cdf5c8d9d7b0c564b105c790d2d2007799'>services: Add file system utilities to profile.</a><span class='msg-avail'>...</span></td><td>Brice Waegeneire</td></tr>
<tr><td><span title='2022-07-14 15:16:23 -0400'>2022-07-14</span></td><td><a href='/guix/commit/gnu/system.scm?id=cbdfa54c7787379c1cce6631acf906b670da8997'>gnu: system: Add fusermount3 to setuid-programs.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-06-15 00:25:20 +0200'>2022-06-15</span></td><td><a href='/guix/commit/gnu/system.scm?id=7046e777212233b89df68379c270b448c45195ce'>system: &lt;operating-system&gt; compiler truly honors the 'system' argument.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-06-06 11:29:51 -0400'>2022-06-06</span></td><td><a href='/guix/commit/gnu/system.scm?id=1d0d46b1c7532461c6243e4af6f208f47d66cd4e'>system: Fix typo, add doc.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-05-21 00:12:31 -0400'>2022-05-21</span></td><td><a href='/guix/commit/gnu/system.scm?id=39a9404c996e5e686ab2d8745a4bbc5597430289'>system: Improve warning when using LUKS mapped devices without UUIDs.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-04-07 00:08:56 +0200'>2022-04-07</span></td><td><a href='/guix/commit/gnu/system.scm?id=400c9ed3d779308e56038305d40cd93acb496180'>services: shepherd: Default to version 0.9.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-03-21 23:03:35 +0100'>2022-03-21</span></td><td><a href='/guix/commit/gnu/system.scm?id=f43dce6ef9b62ca060af95ca97007ae6dde1289f'>system: Use 'shadow-with-man-pages' in %BASE-PACKAGES-UTILS.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-03-16 15:48:52 +0100'>2022-03-16</span></td><td><a href='/guix/commit/gnu/system.scm?id=47960b55268220ca1cb7d2fed41c53873181d816'>system: Improve 'read-boot-parameters' incompatibility diagnostic.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-03-07 22:53:58 +0200'>2022-03-07</span></td><td><a href='/guix/commit/gnu/system.scm?id=34ba6e0616a4f8cee672ea23a9ed6fbb1b155a4b'>system: Set kernel name for riscv64-linux.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>