From: https://github.com/PDAL/PDAL/commit/a3a8d6f1759f848b1ec6f3a2fcb3e6b40f12d892
From: Howard Butler <hobu.inc@gmail.com>
Date: Thu, 19 Jan 2023 09:58:47 -0600
Subject: [PATCH] Make Abseil/re2 an opt-in, not required when Abseil is lazily
 found (#3948)

* address #3944, Abseil/re2 being required. It is now an opt-in

* missing endif()

* WITH_ABSEIL FALSE
---
 cmake/gtest.cmake   | 48 ++++++++++++++++++++++++---------------------
 cmake/options.cmake |  4 ++++
 2 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/cmake/gtest.cmake b/cmake/gtest.cmake
index c0a0d44ba5..df230a10b2 100644
--- a/cmake/gtest.cmake
+++ b/cmake/gtest.cmake
@@ -4,32 +4,36 @@ if (MSVC)
     option(gtest_force_shared_crt "Always use shared Visual C++ run-time DLL" ON)
 endif()
 
-set(GOOGLETEST_VERSION 1.10.0)
+set(GOOGLETEST_VERSION 1.12.1)
 add_subdirectory(vendor/gtest)
 
 set(FPHSA_NAME_MISMATCHED 1) # Suppress warnings, see https://cmake.org/cmake/help/v3.17/module/FindPackageHandleStandardArgs.html
-find_package(absl QUIET)
-set(FPHSA_NAME_MISMATCHED 0)
 
-if (absl_FOUND)
-    find_package(re2 REQUIRED)
 
-    if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.13.0")
-        cmake_policy(SET CMP0079 NEW)
+if (WITH_ABSEIL)
+    find_package(absl REQUIRED)
+    set(FPHSA_NAME_MISMATCHED 0)
+
+    if (absl_FOUND)
+        find_package(re2 REQUIRED)
+
+        if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.13.0")
+            cmake_policy(SET CMP0079 NEW)
+        endif()
+        target_compile_definitions(gtest PUBLIC GTEST_HAS_ABSL=1)
+        target_compile_definitions(gtest_main PUBLIC GTEST_HAS_ABSL=1)
+        target_link_libraries(gtest PRIVATE absl::algorithm
+                                            absl::base
+                                            absl::flags
+                                            absl::flags_internal
+                                            absl::flags_usage
+                                            absl::flags_commandlineflag
+                                            absl::flags_parse
+                                            absl::debugging
+                                            absl::numeric
+                                            absl::strings
+                                            absl::utility
+                                            absl::failure_signal_handler)
+        target_link_libraries(gtest PUBLIC re2::re2)
     endif()
-    target_compile_definitions(gtest PUBLIC GTEST_HAS_ABSL=1)
-    target_compile_definitions(gtest_main PUBLIC GTEST_HAS_ABSL=1)
-    target_link_libraries(gtest PRIVATE absl::algorithm
-                                        absl::base
-                                        absl::flags
-                                        absl::flags_internal
-                                        absl::flags_usage
-                                        absl::flags_commandlineflag
-                                        absl::flags_parse
-                                        absl::debugging
-                                        absl::numeric
-                                        absl::strings
-                                        absl::utility
-                                        absl::failure_signal_handler)
-    target_link_libraries(gtest PRIVATE re2::re2)
 endif()
diff --git a/cmake/options.cmake b/cmake/options.cmake
index 73be6788b2..ca3460e629 100644
--- a/cmake/options.cmake
+++ b/cmake/options.cmake
@@ -105,6 +105,10 @@ add_feature_info("Unit tests" WITH_TESTS "PDAL unit tests")
 option(ENABLE_CTEST
     "Enable CTest to support submissions of results to CDash at http://cdash.org" FALSE)
 
+option(WITH_ABSEIL
+    "Choose if PDAL should be built with Abseil support for testing" FALSE)
+add_feature_info("Abseil debugging support " WITH_ABSEIL "unit tests")
+
 #
 # Choose dependent options
 #