Cannot swap mac_unopt orchestrator from Mac to Linux #124912
Description
To move some capacity from Macs to Linux, I tried to change the mac_unopt conductor from Macs to Linux since the subbuilds need to run on a Mac, but the top level build does not.
In flutter/engine#41184 I added a new bringup Linux mac_unopt builder, which looked like it passed based on the led command run by @keyonghan https://luci-milo.appspot.com/raw/build/logs.chromium.org/flutter/led/keyonghan_google.com/49f579a1636ddec2ffc05cb6053196a4472f5e4f69034386f88824356c479621/+/build.proto.
However when I tried to run Linux mac_unopt in try by removing bringup flutter/engine#41226 it consistently fails: https://ci.chromium.org/p/flutter/builders/try/Linux%20mac_unopt/3.
FAILED: obj/third_party/skia/src/gpu/ganesh/mtl/gpu.GrMtlGpu.o
/Volumes/Work/s/w/ir/cache/goma/client/gomacc ../../buildtools/mac-x64/clang/bin/clang++ -MD -MF obj/third_party/skia/src/gpu/ganesh/mtl/gpu.GrMtlGpu.o.d -DUSE_OPENSSL=1 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D_FORTIFY_SOURCE=2 -D_LIBCPP_DISABLE_AVAILABILITY=1 -D_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS -D_LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS -D_DEBUG -DSK_ENABLE_DUMP_GPU -DSK_DISABLE_AAA -DSK_LEGACY_IGNORE_DRAW_VERTICES_BLEND_WITH_NO_SHADER -DSK_DISABLE_LEGACY_SHADERCONTEXT -DSK_DISABLE_LOWP_RASTER_PIPELINE -DSK_FORCE_RASTER_PIPELINE_BLITTER -DSK_METAL_WAIT_UNTIL_SCHEDULED -DSK_DISABLE_EFFECT_DESERIALIZATION -DSK_ENABLE_SKSL -DSK_ENABLE_PRECOMPILE -DSK_GANESH -DSK_USE_PERFETTO -DSK_LEGACY_LAYER_BOUNDS_EXPANSION -DSK_ENABLE_API_AVAILABLE -DSK_GAMMA_APPLY_TO_A8 -DSKIA_IMPLEMENTATION=1 -DSK_GL -DSK_METAL -I../.. -Igen -I../../third_party/libcxx/include -I../../third_party/libcxxabi/include -I../../build/secondary/third_party/libcxx/config -I../../third_party/skia -isysroot /Volumes/Work/s/w/ir/cache/osx_sdk/XCode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -mmacosx-version-min=10.14.0 -fno-strict-aliasing -fstack-protector-all -arch x86_64 -fcolor-diagnostics -Wall -Wextra -Wendif-labels -Werror -Wno-missing-field-initializers -Wno-unused-parameter -Wno-unused-but-set-parameter -Wno-unused-but-set-variable -Wno-implicit-int-float-conversion -Wno-c99-designator -Wno-deprecated-copy -Wno-psabi -Wno-unqualified-std-cast-call -Wno-non-c-typedef-for-linkage -Wno-range-loop-construct -Wunguarded-availability -Wno-deprecated-declarations -fvisibility=hidden -Wstring-conversion -Wnewline-eof -O0 -g2 -fvisibility-inlines-hidden -std=c++17 -fno-rtti -nostdinc++ -nostdinc++ -fvisibility=hidden -fno-exceptions -stdlib=libc++ -fobjc-arc -fvisibility-inlines-hidden -fobjc-call-cxx-cdtors -std=c++17 -fno-rtti -nostdinc++ -nostdinc++ -fvisibility=hidden -fno-exceptions -c ../../third_party/skia/src/gpu/ganesh/mtl/GrMtlGpu.mm -o obj/third_party/skia/src/gpu/ganesh/mtl/gpu.GrMtlGpu.o
../../third_party/skia/src/gpu/ganesh/mtl/GrMtlGpu.mm:830:14: error: 'MTLPixelFormatB5G6R5Unorm' is unavailable: not available on macOS
case MTLPixelFormatB5G6R5Unorm: return GrColorType::kBGR_565;
^
/Volumes/Work/s/w/ir/cache/osx_sdk/XCode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/Metal.framework/Headers/MTLPixelFormat.h:43:5: note: 'MTLPixelFormatB5G6R5Unorm' has been explicitly marked unavailable here
MTLPixelFormatB5G6R5Unorm API_AVAILABLE(ios(8.0)) API_UNAVAILABLE(macos, macCatalyst) = 40,
^
../../third_party/skia/src/gpu/ganesh/mtl/GrMtlGpu.mm:831:14: error: 'MTLPixelFormatABGR4Unorm' is unavailable: not available on macOS
case MTLPixelFormatABGR4Unorm: return GrColorType::kABGR_4444;
^
/Volumes/Work/s/w/ir/cache/osx_sdk/XCode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/Metal.framework/Headers/MTLPixelFormat.h:45:5: note: 'MTLPixelFormatABGR4Unorm' has been explicitly marked unavailable here
MTLPixelFormatABGR4Unorm API_AVAILABLE(ios(8.0)) API_UNAVAILABLE(macos, macCatalyst) = 42,
^
2 errors generated.
The succeeding led drone run os is Mac-12 https://luci-milo.appspot.com/raw/build/logs.chromium.org/flutter/led/flutter-prod-builder_chops-service-accounts.iam.gserviceaccount.com/04b1344718673d9477284ef29e13ff48ff9ccb363670acf44e75b8accf5a2144/+/build.proto
But the failing one in try is passing os Ubuntu even though the bot is Mac https://ci.chromium.org/p/flutter/builders/try/Linux%20Engine%20Drone/724770