macOS10.14: webengine not compiling

cmake 
-DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ 
-DBUILD_EXAMPLES=OFF -DCMAKE_BUILD_TYPE=Release -DFEATURE_framework=ON 
-DPostgreSQL_ROOT=/Applications/Postgres.app/Contents/Versions/9.6/bin/..
 -DQT_BUILD_TESTS=OFF -GNinja /Users/qt/RTA/src-6.2.0 
-DCMAKE_INSTALL_PREFIX:PATH=/Users/qt/RTA/src-6.2.0/qtbase

[5411/27114] STAMP obj/components/resources/ssl/ssl_error_assistant/make_ssl_error_assistant_protobuf.stamp
[5412/27114] CXX obj/third_party/snappy/bundled_snappy/snappy.o FAILED: obj/third_party/snappy/bundled_snappy/snappy.o 
../../../../../../../../../Applications/Xcode11.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -MMD -MF obj/third_party/snappy/bundled_snappy/snappy.o.d -DHAVE_CONFIG_H -DOFFICIAL_BUILD -DTOOLKIT_QT -D_LIBCPP_HAS_NO_ALIGNED_ALLOCATION -DCR_XCODE_VERSION=1131 -D__ASSERT_MACROS_DEFINE_VERSIONS_WITHOUT_UNDERSCORES=0 -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -Igen -I../../../3rdparty/chromium -I../../../3rdparty/chromium/third_party/snappy/src -I../../../3rdparty/chromium/third_party/snappy/mac -fno-delete-null-pointer-checks -fno-strict-aliasing -fstack-protector -Wno-unknown-argument -Wno-unknown-attributes -Wno-unknown-warning-option -Wno-unknown-pragmas -fcolor-diagnostics -fmerge-all-constants -arch x86_64 -O2 -fno-omit-frame-pointer -g0 -isysroot ../../../../../../../../../Applications/Xcode11.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -mmacosx-version-min=10.14 -fvisibility=hidden -Wheader-hygiene -Wstring-conversion -Wtautological-overlap-compare -Wall -Wno-unused-variable -Wno-misleading-indentation -Wunguarded-availability -Wno-missing-field-initializers -Wno-unused-parameter -Wno-c++11-narrowing -Wno-unneeded-internal-declaration -Wno-undefined-var-template -Wno-psabi -Wno-ignored-pragma-optimize -Wno-implicit-int-float-conversion -Wno-final-dtor-non-final-class -Wno-builtin-assume-aligned-alignment -Wno-deprecated-copy -Wno-non-c-typedef-for-linkage -Wno-max-tokens -Wno-parentheses-equality -Wno-tautological-compare -Wno-thread-safety-attributes -Wno-undefined-bool-conversion -Wno-tautological-undefined-compare -std=c++14 -fno-trigraphs -Wno-trigraphs -stdlib=libc++ -fno-exceptions -fno-rtti -fvisibility-inlines-hidden -c ../../../3rdparty/chromium/third_party/snappy/src/snappy.cc -o obj/third_party/snappy/bundled_snappy/snappy.o
../../../3rdparty/chromium/third_party/snappy/src/snappy.cc:1033:36: error: invalid output constraint '=@ccz' in asm
      : [tag_type] "+r"(tag_type), "=@ccz"(is_literal));
1 error generated.
[5413/27114] CC obj/third_party/libjpeg_turbo/libjpeg/jcapimin.o
[5414/27114] ACTION //content/browser/content_index:content_index_proto_gen(//build/toolchain/mac:clang_x64)
[5415/27114] CXX obj/content/browser/background_sync/background_sync_proto/background_sync.pb.o
[5416/27114] CXX obj/components/variations/proto/proto/study.pb.o
[5417/27114] CXX obj/content/browser/background_fetch/background_fetch_proto/background_fetch.pb.o
[5418/27114] CXX obj/content/browser/cache_storage/cache_storage_proto/cache_storage.pb.o
[5419/27114] CC obj/third_party/sqlite/chromium_sqlite3/sqlite3_shim.o
 ninja: build stopped: subcommand failed.
 FAILED: qtwebengine/src/core/Release/x86_64/QtWebEngineCore.stamp qtwebengine/src/core/Release/x86_64/QtWebEngineCore /Users/qt/RTA/src-6.2.0/qtwebengine/src/core/Release/x86_64/QtWebEngineCore.stamp /Users/qt/RTA/src-6.2.0/qtwebengine/src/core/Release/x86_64/QtWebEngineCore 
cd /Users/qt/RTA/src-6.2.0/qtwebengine/src/core && /usr/local/bin/ninja -j8 -C /Users/qt/RTA/src-6.2.0/qtwebengine/src/core/Release/x86_64 QtWebEngineCore
 ninja: build stopped: subcommand failed.