Help/release/3.21.rst

@@ -310,3 +310,5 @@ Changes made since CMake 3.21.0 include the following.
 
 * ``CUDA`` targets with :prop_tgt:`CUDA_SEPARABLE_COMPILATION` enabled are now
   correctly generated in non-root directories.
+
+* Restore support for a legacy platform Mac OS X 10.4 (Tiger).

Modules/Platform/Darwin.cmake

@@ -47,7 +47,12 @@ set(CMAKE_SHARED_MODULE_PREFIX "lib")
 set(CMAKE_SHARED_MODULE_SUFFIX ".so")
 set(CMAKE_MODULE_EXISTS 1)
 set(CMAKE_DL_LIBS "")
-set(CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG "-Wl,-rpath,")
+
+# The -rpath flag is not supported on Mac OS X 10.4 Tiger and older.
+# Enable it for iOS and newer versions of macOS.
+if(NOT DEFINED DARWIN_MAJOR_VERSION OR NOT "${DARWIN_MAJOR_VERSION}" LESS 9)
+  set(CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG "-Wl,-rpath,")
+endif()
 
 foreach(lang C CXX OBJC OBJCXX)
   set(CMAKE_${lang}_OSX_COMPATIBILITY_VERSION_FLAG "-compatibility_version ")