I have Configured my build with:

mkdir build-qt
cd build-qt
../configure -platform android-clang -prefix /misc/work/Android/qtandroid -android-ndk /misc/work/Android/Sdk/ndk/25.1.8937393/ -android-sdk /misc/work/Android/Sdk/ -qt-host-path /misc/work/Android/qt-6.4.0

The /misc/work/Android/qt-6.4.0 is the same source built for linux I wish to keep this work separate from my other linux builds.

After building for a while I get the following:

cmake --build . -j 1
[1099/5476] Building CXX object qtmultimedia/src/plugins/multimedia/ffmpeg/CMakeFiles/QFFmpegMediaPlugin.dir/QFFmpegMediaPlugin_autogen/mocs_compilation.cpp.o
FAILED: qtmultimedia/src/plugins/multimedia/ffmpeg/CMakeFiles/QFFmpegMediaPlugin.dir/QFFmpegMediaPlugin_autogen/mocs_compilation.cpp.o
/misc/work/Android/Sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/linux-x86_64/bin/clang++ --target=armv7-none-linux-androideabi23 --sysroot=/misc/work/Android/Sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/linux-x86_64/sysroot -DQFFmpegMediaPlugin_EXPORTS -DQT_COMPILING_FFMPEG -DQT_CORE_LIB -DQT_DEPRECATED_WARNINGS -DQT_DEPRECATED_WARNINGS_SINCE=0x070000 -DQT_DISABLE_DEPRECATED_BEFORE=0x050000 -DQT_GUI_LIB -DQT_MULTIMEDIA_LIB -DQT_NETWORK_LIB -DQT_NO_DEBUG -DQT_NO_EXCEPTIONS -DQT_NO_JAVA_STYLE_ITERATORS -DQT_NO_NARROWING_CONVERSIONS_IN_CONNECT -DQT_PLUGIN -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtmultimedia/src/plugins/multimedia/ffmpeg/QFFmpegMediaPlugin_autogen/include -I/misc/work/Android/qt-everywhere-src-6.4.0/qtmultimedia/src/plugins/multimedia/ffmpeg -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtmultimedia/src/plugins/multimedia/ffmpeg -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtbase/include -I/include -I/misc/work/Android/qt-everywhere-src-6.4.0/qtmultimedia/src/plugins/multimedia/ffmpeg/../android/wrappers/jni -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtmultimedia/src/multimedia -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtbase/include/QtMultimedia/6.4.0 -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtbase/include/QtMultimedia/6.4.0/QtMultimedia -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtbase/src/corelib -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtbase/include/QtCore/6.4.0 -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtbase/include/QtCore/6.4.0/QtCore -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtbase/include/QtCore -I/misc/work/Android/qt-everywhere-src-6.4.0/qtbase/mkspecs/android-clang -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtbase/src/gui -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtbase/include/QtGui/6.4.0 -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtbase/include/QtGui/6.4.0/QtGui -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtbase/include/QtGui -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtbase/include/QtMultimedia -I/misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtbase/include/QtNetwork -isystem /usr/local/include -g -DANDROID -fdata-sections -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -D_FORTIFY_SOURCE=2 -march=armv7-a -mthumb -Wformat -Werror=format-security -DNDEBUG -Oz -fPIC -fvisibility=hidden -fvisibility-inlines-hidden -Wall -Wextra -fno-exceptions -pthread -std=c++17 -MD -MT qtmultimedia/src/plugins/multimedia/ffmpeg/CMakeFiles/QFFmpegMediaPlugin.dir/QFFmpegMediaPlugin_autogen/mocs_compilation.cpp.o -MF qtmultimedia/src/plugins/multimedia/ffmpeg/CMakeFiles/QFFmpegMediaPlugin.dir/QFFmpegMediaPlugin_autogen/mocs_compilation.cpp.o.d -o qtmultimedia/src/plugins/multimedia/ffmpeg/CMakeFiles/QFFmpegMediaPlugin.dir/QFFmpegMediaPlugin_autogen/mocs_compilation.cpp.o -c /misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtmultimedia/src/plugins/multimedia/ffmpeg/QFFmpegMediaPlugin_autogen/mocs_compilation.cpp
In file included from /misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtmultimedia/src/plugins/multimedia/ffmpeg/QFFmpegMediaPlugin_autogen/mocs_compilation.cpp:2:
In file included from /misc/work/Android/qt-everywhere-src-6.4.0/build-qt/qtmultimedia/src/plugins/multimedia/ffmpeg/QFFmpegMediaPlugin_autogen/WM3ZFXPYDJ/moc_androidsurfacetexture_p.cpp:9:
In file included from /misc/work/Android/Sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/include/c++/v1/memory:658:
In file included from /misc/work/Android/Sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/include/c++/v1/__config:218:
In file included from /usr/local/include/features.h:474:
/usr/local/include/gnu/stubs.h:7:11: fatal error: 'gnu/stubs-32.h' file not found
"# include <gnu/stubs-32.h>"
^~~~~~~~~~~~~~~~
1 error generated.
ninja: build stopped: subcommand failed.

This says to me that "__linux__" is defined somewhere but I have no clue has to where.

Can any one help please.