--- swift-corelibs-libdispatch/tests/CMakeLists.txt.orig	2023-06-15 00:55:45 UTC
+++ swift-corelibs-libdispatch/tests/CMakeLists.txt
@@ -47,6 +47,7 @@ add_executable(bsdtestharness
 
 add_executable(bsdtestharness
                bsdtestharness.c)
+target_compile_options(bsdtestharness PRIVATE -fblocks)
 target_include_directories(bsdtestharness
                            PRIVATE
                              ${CMAKE_CURRENT_BINARY_DIR}
