dtk@DTK mame % make -j1 SDL_INSTALL_ROOT=/opt/arm VERBOSE=1 macosx_arm64_clang
Clang 12.0.0 detected
/Applications/Xcode-beta.app/Contents/Developer/usr/bin/make -R verbose=1 -C build/projects/sdl/mame/gmake-osx-clang config=release64 precompile
/Applications/Xcode-beta.app/Contents/Developer/usr/bin/make -R verbose=1 -C build/projects/sdl/mame/gmake-osx-clang config=release64
Compiling src/osd/modules/input/input_common.cpp...
clang++    -MMD -MP -MP -DPTR64=1 -DNDEBUG -DCRLF=2 -DLSB_FIRST -DFLAC__NO_DLL -DPUGIXML_HEADER_ONLY -DMAME_NOASM -DLUA_COMPAT_ALL -DLUA_COMPAT_5_1 -DLUA_COMPAT_5_2 -DSDLMAME_NO_X11 -DUSE_XINPUT=0 -DUSE_XINPUT_WII_LIGHTGUN_HACK=0 -DSDLMAME_SDL2=1 -DOSD_SDL -DSDLMAME_UNIX -DSDLMAME_MACOSX -DSDLMAME_DARWIN -DUSE_OPENGL=1 -D__STDC_LIMIT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS -DIMGUI_DISABLE_OBSOLETE_FUNCTIONS -DUSE_QTDEBUG=0 -I"../../../../../3rdparty/bx/include/compat/osx" -I"../../../../../3rdparty/asio/include" -I"../../../../../3rdparty/bgfx/examples/common" -I"../../../../../3rdparty/bgfx/include" -I"../../../../../3rdparty/bgfx/3rdparty" -I"../../../../../3rdparty/bgfx/3rdparty/khronos" -I"../../../../../3rdparty/bx/include" -I"../../../../../3rdparty/rapidjson/include" -I"../../../../../3rdparty/portaudio/include" -I"../../../../../3rdparty/portmidi/pm_common" -I"../../../../../src/emu" -I"../../../../../src/devices" -I"../../../../../src/osd" -I"../../../../../src/lib" -I"../../../../../src/lib/util" -I"../../../../../src/osd/modules/file" -I"../../../../../src/osd/modules/render" -I"../../../../../3rdparty" -I"../../../../../src/osd/sdl"  -m64 -arch arm64 -pipe -Werror -O3 -fno-strict-aliasing -Wno-unknown-pragmas -Wall -Wcast-align -Wundef -Wformat-security -Wwrite-strings -Wno-sign-compare -Wno-conversion -Wno-error=deprecated-declarations -Wno-cast-align -Wno-tautological-compare -Wno-unused-value -Wno-constant-logical-operand -fdiagnostics-show-note-include-stack -Wno-unknown-warning-option -Wno-extern-c-compat -Wno-unknown-attributes -Wno-ignored-qualifiers -Wno-pragma-pack -m64 -DHAVE_IMMINTRIN_H=1 -F/Library/Frameworks/ -std=c++14 -Woverloaded-virtual -include /Users/dtk/code/mame/src/osd/sdl/sdlprefix.h -o "../../../../osx_clang/obj/x64/Release/osd_sdl/src/osd/modules/input/input_common.o" -c "../../../../../src/osd/modules/input/input_common.cpp"
../../../../../src/osd/modules/input/input_common.cpp:36:10: fatal error: 'SDL2/SDL.h' file not found
#include <SDL2/SDL.h>
         ^~~~~~~~~~~~
1 error generated.
make[2]: *** [../../../../osx_clang/obj/x64/Release/osd_sdl/src/osd/modules/input/input_common.o] Error 1
make[1]: *** [osd_sdl] Error 2
make: *** [macosx_arm64_clang] Error 2