Disable installing gtest when cmake --install (#37)

* disable INSTALL_GTEST

* update comments

.ci/docker/ubuntu.Dockerfile

@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-# Using a non-LTS Ubuntu, just until CMake 3.24 is available on Ubuntu 24.04.
+# Using a non-LTS Ubuntu, just until CMake 3.25 is available on Ubuntu 24.04
 FROM ubuntu:23.10
 
 # Install dependencies,

CMakeLists.txt

@@ -1,7 +1,6 @@
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-# TODO Darius: Find CMake minimum required version.
-cmake_minimum_required(VERSION 3.23)
+cmake_minimum_required(VERSION 3.25)
 
 project(
   beman.exemplar # CMake Project Name, which is also the name of the top-level
@@ -15,13 +14,18 @@ include(FetchContent)
 if(BUILD_TESTING)
   enable_testing()
 
-  # Fetch GoogleTest
-  FetchContent_Declare(
-    googletest
-    GIT_REPOSITORY https://github.com/google/googletest.git
-    GIT_TAG f8d7d77c06936315286eb55f8de22cd23c188571 # release-1.14.0
-    EXCLUDE_FROM_ALL CMAKE_ARGS -DBUILD_TESTING=OFF)
-  FetchContent_MakeAvailable(googletest)
+  block()
+    # Disable installing google test dependency on cmake --install
+    set(INSTALL_GTEST OFF)
+
+    # Fetch GoogleTest
+    FetchContent_Declare(
+      googletest
+      GIT_REPOSITORY https://github.com/google/googletest.git
+      GIT_TAG f8d7d77c06936315286eb55f8de22cd23c188571 # release-1.14.0
+      EXCLUDE_FROM_ALL CMAKE_ARGS -DBUILD_TESTING=OFF)
+    FetchContent_MakeAvailable(googletest)
+  endblock()
 endif()
 
 add_subdirectory(src/beman/exemplar)