The following build error when trying to build WPE with this non-default switches:

$ Tools/Scripts/build-webkit --wpe --no-fatal-warnings --no-experimental-features --cmakeargs='-DENABLE_WPE_QT_API=OFF -DENABLE_THUNDER=OFF -DENABLE_DOCUMENTATION=OFF -DENABLE_INTROSPECTION=OFF -DUSE_SOUP2=ON -DUSE_AVIF=OFF -DUSE_GSTREAMER_TRANSCODER=OFF'
[...]
In file included from /usr/include/c++/10/memory:83,
                 from WTF/Headers/wtf/StdLibExtras.h:30,
                 from WTF/Headers/wtf/FastMalloc.h:26,
                 from ../../Source/WebCore/config.h:59,
                 from ../../Source/WebCore/Modules/mediarecorder/MediaRecorderProvider.cpp:26,
                 from WebCore/DerivedSources/unified-sources/UnifiedSource-cbdfe323-20.cpp:1:
/usr/include/c++/10/bits/unique_ptr.h: In instantiation of ‘void std::default_delete<_Tp>::operator()(_Tp*) const [with _Tp = WebCore::MediaRecorderPrivate]’:
/usr/include/c++/10/bits/unique_ptr.h:361:17:   required from ‘std::unique_ptr<_Tp, _Dp>::~unique_ptr() [with _Tp = WebCore::MediaRecorderPrivate; _Dp = std::default_delete<WebCore::MediaRecorderPrivate>]’
../../Source/WebCore/Modules/mediarecorder/MediaRecorderProvider.cpp:52:12:   required from here
/usr/include/c++/10/bits/unique_ptr.h:83:16: error: invalid application of ‘sizeof’ to incomplete type ‘WebCore::MediaRecorderPrivate’
   83 |  static_assert(sizeof(_Tp)>0,
      |                ^~~~~~~~~~~