feat: add an option to configure native backend on windows & linux

flutter/linux/CMakeLists.txt

@@ -3,6 +3,8 @@
 # the plugin to fail to compile for some customers of the plugin.
 cmake_minimum_required(VERSION 3.10)
 
+set(SENTRY_BACKEND "crashpad" CACHE STRING "The sentry backend responsible for reporting crashes" FORCE)
+
 include("${CMAKE_CURRENT_SOURCE_DIR}/../sentry-native/sentry-native.cmake")
 
 # Even though sentry_flutter doesn't actually provide a useful plugin, we need to accommodate the Flutter tooling.

flutter/sentry-native/sentry-native.cmake

@@ -2,9 +2,16 @@ load_cache("${CMAKE_CURRENT_LIST_DIR}" READ_WITH_PREFIX SENTRY_NATIVE_ repo vers
 message(STATUS "Fetching Sentry native version: ${SENTRY_NATIVE_version} from ${SENTRY_NATIVE_repo}")
 
 set(SENTRY_SDK_NAME "sentry.native.flutter" CACHE STRING "The SDK name to report when sending events." FORCE)
-set(SENTRY_BACKEND "crashpad" CACHE STRING "The sentry backend responsible for reporting crashes" FORCE)
 set(SENTRY_BUILD_SHARED_LIBS ON CACHE BOOL "Build shared libraries (.dll/.so) instead of static ones (.lib/.a)" FORCE)
 
+# Note: the backend is also set in linux/CMakeLists.txt and windows/CMakeLists.txt. This overwrites those if user sets an env var.
+if("$ENV{SENTRY_NATIVE_BACKEND}" STREQUAL "")
+    # Until sentry-dart v9, we disable native backend by default.
+    set(SENTRY_BACKEND "none" CACHE STRING "The sentry backend responsible for reporting crashes" FORCE)
+else()
+    set(SENTRY_BACKEND $ENV{SENTRY_NATIVE_BACKEND} CACHE STRING "The sentry backend responsible for reporting crashes" FORCE)
+endif()
+
 include(FetchContent)
 FetchContent_Declare(
     sentry-native
@@ -17,15 +24,19 @@ FetchContent_MakeAvailable(sentry-native)
 
 # List of absolute paths to libraries that should be bundled with the plugin.
 # This list could contain prebuilt libraries, or libraries created by an external build triggered from this build file.
-if(WIN32)
-    set(sentry_flutter_bundled_libraries
-        $<TARGET_FILE:crashpad_handler>
-        $<TARGET_FILE:crashpad_wer>
-        PARENT_SCOPE)
+if(SENTRY_BACKEND STREQUAL "crashpad")
+    if(WIN32)
+        set(sentry_flutter_bundled_libraries
+            $<TARGET_FILE:crashpad_handler>
+            $<TARGET_FILE:crashpad_wer>
+            PARENT_SCOPE)
+    else()
+        set(sentry_flutter_bundled_libraries
+            $<TARGET_FILE:crashpad_handler>
+            PARENT_SCOPE)
+    endif()
 else()
-    set(sentry_flutter_bundled_libraries
-        $<TARGET_FILE:crashpad_handler>
-        PARENT_SCOPE)
+    set(sentry_flutter_bundled_libraries "" PARENT_SCOPE)
 endif()
 
 # `*_plugin` is the name of the plugin library as expected by flutter.