From 068f60c92b74ed5d8c5ea651a4217169752b3caa Mon Sep 17 00:00:00 2001
From: Aaron Jomy <aaronjomyjoseph@gmail.com>
Date: Wed, 15 Oct 2025 14:37:26 +0200
Subject: [PATCH] Try `find_package(gtest)` when configuring testing

From https://github.com/root-project/root/pull/20011/commits/72b979a1646b4c758b0cc2393087a132af9816fc
Prevents failures in offline builds that cannot fetch gtest. We now first look for gtest and suggest disabling testing if it is not found
---
 unittests/CMakeLists.txt | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/unittests/CMakeLists.txt b/unittests/CMakeLists.txt
index f13b85f68..3d13205b5 100644
--- a/unittests/CMakeLists.txt
+++ b/unittests/CMakeLists.txt
@@ -4,7 +4,11 @@ enable_testing()
 
 # LLVM builds (not installed llvm) provides gtest.
 if (NOT TARGET GTest::gtest AND NOT TARGET gtest)
-  include(GoogleTest)
+  find_package(GTest)
+  if (NOT GTest_FOUND)
+    message(WARNING "CppInterOp could not find GTest. Provide the package or set CPPINTEROP_ENABLE_TESTING=OFF to disable this warning.")
+    return()
+  endif()
 endif()
 
 if(EMSCRIPTEN)