This patch allows the build process to use the provided dependencies instead
of adding their source as CMake sub-directories (in which case "make install"
would install googletest's and googlebenchmark's libraries and headers).

diff --git a/CMakeLists.txt b/CMakeLists.txt
index bcae6b5..ff6710d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -21,7 +21,7 @@ IF(FXDIV_BUILD_TESTS)
 ENDIF()
 
 # ---[ Download deps
-IF(FXDIV_BUILD_TESTS AND NOT DEFINED GOOGLETEST_SOURCE_DIR)
+IF(FALSE)
   MESSAGE(STATUS "Downloading Google Test to ${CMAKE_BINARY_DIR}/googletest-source (define GOOGLETEST_SOURCE_DIR to avoid it)")
   CONFIGURE_FILE(cmake/DownloadGoogleTest.cmake "${CMAKE_BINARY_DIR}/googletest-download/CMakeLists.txt")
   EXECUTE_PROCESS(COMMAND "${CMAKE_COMMAND}" -G "${CMAKE_GENERATOR}" .
@@ -31,7 +31,7 @@ IF(FXDIV_BUILD_TESTS AND NOT DEFINED GOOGLETEST_SOURCE_DIR)
   SET(GOOGLETEST_SOURCE_DIR "${CMAKE_BINARY_DIR}/googletest-source" CACHE STRING "Google Test source directory")
 ENDIF()
 
-IF(FXDIV_BUILD_BENCHMARKS AND NOT DEFINED GOOGLEBENCHMARK_SOURCE_DIR)
+IF(FALSE)
   MESSAGE(STATUS "Downloading Google Benchmark to ${CMAKE_BINARY_DIR}/googlebenchmark-source (define GOOGLEBENCHMARK_SOURCE_DIR to avoid it)")
   CONFIGURE_FILE(cmake/DownloadGoogleBenchmark.cmake "${CMAKE_BINARY_DIR}/googlebenchmark-download/CMakeLists.txt")
   EXECUTE_PROCESS(COMMAND "${CMAKE_COMMAND}" -G "${CMAKE_GENERATOR}" .
@@ -54,7 +54,7 @@ INSTALL(FILES include/fxdiv.h DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 
 IF(FXDIV_BUILD_TESTS)
   # ---[ Build google test
-  IF(NOT TARGET gtest)
+  IF(FALSE)
     SET(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
     ADD_SUBDIRECTORY(
       "${GOOGLETEST_SOURCE_DIR}"
@@ -78,7 +78,7 @@ ENDIF()
 
 IF(FXDIV_BUILD_BENCHMARKS)
   # ---[ Build google benchmark
-  IF(NOT TARGET benchmark)
+  IF(FALSE)
     SET(BENCHMARK_ENABLE_TESTING OFF CACHE BOOL "" FORCE)
     ADD_SUBDIRECTORY(
       "${GOOGLEBENCHMARK_SOURCE_DIR}"
q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=f441a149b400d289224a78a7c13c8690080d0926'>root</a>/<a href='/guix/log/etc?id=f441a149b400d289224a78a7c13c8690080d0926'>etc</a>/<a href='/guix/log/etc/guix-daemon.service.in?id=f441a149b400d289224a78a7c13c8690080d0926'>guix-daemon.service.in</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/etc/guix-daemon.service.in?id=f441a149b400d289224a78a7c13c8690080d0926&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-07-07 23:54:20 -0400'>2021-07-07</span></td><td><a href='/guix/commit/etc/guix-daemon.service.in?id=4cbe0127a668cbcc64087c5d311308b59d39b104'>guix-install.sh: Prompt for configuring substitutes discovery.</a><span class='msg-avail'>...<span class='msg-tooltip'>Also ensure prompt_yes_no always print the message with a trailing space,
which is more pleasing to the eye.

* etc/guix-daemon.conf.in &lt;--discover=no&gt;: New guix-daemon option.
* etc/guix-daemon.service.in: Likewise.
* etc/init.d/guix-daemon.in: Likewise.
* etc/openrc/guix-daemon.in: Likewise.
* etc/guix-install.sh (configure_substitute_discovery): New procedure.
(sys_enable_guix_daemon): Ask the user whether automatic substitute discovery
should be enabled.  Set the '--discover' argument accordingly.
(prompt_yes_no): Add a trailing space to the message.
(sys_authorize_build_farms): Remove trailing space from the message argument.
* NEWS (Distribution): Add news.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2019-06-05 11:48:55 +0200'>2019-06-05</span></td><td><a href='/guix/commit/etc/guix-daemon.service.in?id=579d17b70dac067f8194ede46513400b91ac136a'>etc: guix-daemon.service.in: Fix GUIX_LOCPATH quoting.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;https://bugs.gnu.org/36074&gt;.

* etc/guix-daemon.service.in: Move the GUIX_LOCPATH environment variable name
inside the quotes.

Signed-off-by: Ricardo Wurmus &lt;rekado@elephly.net&gt;
</span></span></td><td>Jack Hill</td></tr>
<tr><td><span title='2019-05-13 23:46:08 +0200'>2019-05-13</span></td><td><a href='/guix/commit/etc/guix-daemon.service.in?id=489d6c0dc03f1d95a3fefa6301f36cac9b50b2c3'>Set 'LC_ALL=en_US.utf8' in systemd '.service' files.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;https://bugs.gnu.org/35671&gt;.

* etc/guix-daemon.service.in (Environment): Quote the 'GUIX_LOCPATH'
value; add 'LC_ALL'.
* etc/guix-publish.service.in (Environment): Likewise.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-11-23 15:42:01 +0100'>2018-11-23</span></td><td><a href='/guix/commit/etc/guix-daemon.service.in?id=e9926f80c6553fde50ce1fcfd38d6370f841efd2'>build: Binary tarball now populates the "current-guix" profile.</a><span class='msg-avail'>...<span class='msg-tooltip'>* Makefile.am (guix-binary.%.tar.xz): Pass
'--profile-name=current-guix'.  Remove glibc and glibc-utf8-locales.
* doc/guix.texi (Binary Installation): Update accordingly.
* etc/guix-install.sh
* etc/guix-install.sh (sys_create_store, sys_enable_guix_daemon)
(sys_authorize_build_farms): Likewise.
* etc/guix-publish.conf.in, etc/guix-publish.service.in,
etc/guix-daemon.conf.in, etc/guix-daemon.service.in: Update file names
accordingly.
</span></span></td><td>Ludovic Courtès</td></tr>