libvpx_intrinsics_*.a not generated when building WebRTC 55 in Release mode for MacOS

[Juan García]

I'm building WebRTC version 55 in Release mode (in Debug is working) for MacOS with these args (args.gn):

target_cpu = "x64"
target_os = "mac"
is_debug = false
rtc_include_tests = false

When I look at libvpx_intrinsics_avx folder (and other with same signature, like libvpx_intrinsics_mmx), I can see that all object files are generated but not static lib file (.a) so I'm getting undefined references from my app. Any clue about?