Fix Issue #1902: Explicitly set CMAKE_OSX_DEPLOYMENT_TARGET to 15.0

CMakeLists.txt

@@ -132,6 +132,9 @@ endif()
 
 # CMake 3.14+ native iOS support sets CMAKE_SYSTEM_NAME to iOS, 3.21+ for tvOS
 if(CMAKE_SYSTEM_NAME STREQUAL "iOS" OR CMAKE_SYSTEM_NAME STREQUAL "tvOS")
+  if(NOT DEFINED CMAKE_OSX_DEPLOYMENT_TARGET)
+    set(CMAKE_OSX_DEPLOYMENT_TARGET "15.0" CACHE STRING "Minimum OS X deployment version")
+  endif()
   set(IOS ON CACHE BOOL "")
   set(FIREBASE_IOS_BUILD ON CACHE BOOL "")
 endif()

cmake/external_rules.cmake

@@ -169,6 +169,10 @@ function(build_external_dependencies)
       set(CMAKE_SUB_CONFIGURE_OPTIONS ${CMAKE_SUB_CONFIGURE_OPTIONS}
           -DCMAKE_OSX_ARCHITECTURES=${CMAKE_OSX_ARCHITECTURES})
     endif()
+    if(CMAKE_OSX_DEPLOYMENT_TARGET)
+      set(CMAKE_SUB_CONFIGURE_OPTIONS ${CMAKE_SUB_CONFIGURE_OPTIONS}
+          -DCMAKE_OSX_DEPLOYMENT_TARGET=${CMAKE_OSX_DEPLOYMENT_TARGET})
+    endif()
   elseif(MSVC)
     # Propagate MSVC build flags.
     set(CMAKE_SUB_CONFIGURE_OPTIONS ${CMAKE_SUB_CONFIGURE_OPTIONS}

release_build_files/readme.md

@@ -615,6 +615,7 @@ code.
 ## Release Notes
 ### Upcoming
 - Changes
+    - General (iOS): Fixed an issue where prebuilt iOS/tvOS frameworks had an incorrect minimum deployment target (minos), which caused linker warnings.
     - Auth (Desktop): Fixed log spam and high CPU utilization when offline by moving `USE_AUTH_EMULATOR` environment variable check to initialization and eliminating per-request logging (#1629).
     - Messaging: Added new Registration methods using Installation Ids.
       Deprecated old Token based methods.