Issue 33164 (commit 51aa35e9e17eef60d04add9619fe2a7eb938358c) introduced numerous new warnings on MacOS:

/Users/remi/src/cpython/Modules/_blake2/impl/blake2b.c:192:9: warning: 'blake2b_init' macro redefined
      [-Wmacro-redefined]
#define blake2b_init BLAKE2_IMPL_NAME(blake2b_init)
        ^
/Users/remi/src/cpython/Modules/_blake2/blake2ns.h:10:9: note: previous definition is here
#define blake2b_init       PyBlake2_blake2b_init
        ^
In file included from /Users/remi/src/cpython/Modules/_blake2/blake2b_impl.c:32:
/Users/remi/src/cpython/Modules/_blake2/impl/blake2b.c:193:9: warning: 'blake2b_init_param' macro redefined
      [-Wmacro-redefined]
#define blake2b_init_param BLAKE2_IMPL_NAME(blake2b_init_param)
        ^
/Users/remi/src/cpython/Modules/_blake2/blake2ns.h:12:9: note: previous definition is here
#define blake2b_init_param PyBlake2_blake2b_init_param
        ^
In file included from /Users/remi/src/cpython/Modules/_blake2/blake2b_impl.c:32:
/Users/remi/src/cpython/Modules/_blake2/impl/blake2b.c:194:9: warning: 'blake2b_init_key' macro redefined
      [-Wmacro-redefined]
#define blake2b_init_key BLAKE2_IMPL_NAME(blake2b_init_key)
        ^
/Users/remi/src/cpython/Modules/_blake2/blake2ns.h:11:9: note: previous definition is here
#define blake2b_init_key   PyBlake2_blake2b_init_key
        ^
In file included from /Users/remi/src/cpython/Modules/_blake2/blake2b_impl.c:32:
/Users/remi/src/cpython/Modules/_blake2/impl/blake2b.c:195:9: warning: 'blake2b_update' macro redefined
      [-Wmacro-redefined]
#define blake2b_update BLAKE2_IMPL_NAME(blake2b_update)
        ^
/Users/remi/src/cpython/Modules/_blake2/blake2ns.h:13:9: note: previous definition is here
#define blake2b_update     PyBlake2_blake2b_update
        ^
In file included from /Users/remi/src/cpython/Modules/_blake2/blake2b_impl.c:32:
/Users/remi/src/cpython/Modules/_blake2/impl/blake2b.c:196:9: warning: 'blake2b_final' macro redefined
      [-Wmacro-redefined]
#define blake2b_final BLAKE2_IMPL_NAME(blake2b_final)
        ^
/Users/remi/src/cpython/Modules/_blake2/blake2ns.h:9:9: note: previous definition is here
#define blake2b_final      PyBlake2_blake2b_final
        ^
In file included from /Users/remi/src/cpython/Modules/_blake2/blake2b_impl.c:32:
/Users/remi/src/cpython/Modules/_blake2/impl/blake2b.c:197:9: warning: 'blake2b' macro redefined [-Wmacro-redefined]
#define blake2b BLAKE2_IMPL_NAME(blake2b)
        ^
/Users/remi/src/cpython/Modules/_blake2/blake2ns.h:7:9: note: previous definition is here
#define blake2b            PyBlake2_blake2b


I'm not sure what should be the public API exactly and where to fix that.