In file included from /app/webkit/Source/WebKit/WebProcess/InjectedBundle/API/glib/WebKitInjectedBundleMain.cpp:22: In file included from /app/webkit/Source/WebKit/WebProcess/InjectedBundle/InjectedBundle.h:28: /app/webkit/Source/WebKit/WebProcess/InjectedBundle/API/APIInjectedBundleBundleClient.h:42:5: error: C++ requires a type specifier for all declarations WTF_MAKE_FAST_ALLOCATED; ^ In file included from /app/webkit/Source/WebKit/WebProcess/InjectedBundle/API/glib/WebKitInjectedBundleMain.cpp:22: In file included from /app/webkit/Source/WebKit/WebProcess/InjectedBundle/InjectedBundle.h:29: In file included from /app/webkit/Source/WebKit/Shared/API/APIObject.h:29: In file included from /app/webkit/WebKitBuild/Release/WTF/Headers/wtf/RefCounted.h:24: In file included from /app/webkit/WebKitBuild/Release/WTF/Headers/wtf/FastMalloc.h:26: In file included from /app/webkit/WebKitBuild/Release/WTF/Headers/wtf/StdLibExtras.h:32: /usr/lib/gcc/x86_64-unknown-linux-gnu/12.2.0/../../../../include/c++/12.2.0/utility:108:111: error: called object type 'const char[75]' is not a function or function pointer void as_const(const _Tp&&) = ("if you use new/delete make sure to include config.h at the top of the file"()); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^ /usr/lib/gcc/x86_64-unknown-linux-gnu/12.2.0/../../../../include/c++/12.2.0/utility:108:10: error: illegal initializer (only variables can be initialized) void as_const(const _Tp&&) = ("if you use new/delete make sure to include config.h at the top of the file"()); ^ In file included from /app/webkit/Source/WebKit/WebProcess/InjectedBundle/API/glib/WebKitInjectedBundleMain.cpp:22: In file included from /app/webkit/Source/WebKit/WebProcess/InjectedBundle/InjectedBundle.h:29: In file included from /app/webkit/Source/WebKit/Shared/API/APIObject.h:29: In file included from /app/webkit/WebKitBuild/Release/WTF/Headers/wtf/RefCounted.h:24: In file included from /app/webkit/WebKitBuild/Release/WTF/Headers/wtf/FastMalloc.h:26: In file included from /app/webkit/WebKitBuild/Release/WTF/Headers/wtf/StdLibExtras.h:33: /usr/lib/gcc/x86_64-unknown-linux-gnu/12.2.0/../../../../include/c++/12.2.0/variant:283:6: error: expected unqualified-id ::("if you use new/delete make sure to include config.h at the top of the file"()) ((void*)std::addressof(_M_storage)) ^ /usr/lib/gcc/x86_64-unknown-linux-gnu/12.2.0/../../../../include/c++/12.2.0/variant:283:83: error: called object type 'const char[75]' is not a function or function pointer ::("if you use new/delete make sure to include config.h at the top of the file"()) ((void*)std::addressof(_M_storage)) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^ /usr/lib/gcc/x86_64-unknown-linux-gnu/12.2.0/../../../../include/c++/12.2.0/variant:374:132: error: called object type 'const char[75]' is not a function or function pointer _Variadic_union(in_place_index_t<_Np>, _Args&&...) = ("if you use new/delete make sure to include config.h at the top of the file"()); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^ ... and so on... Source/WebKit/WebProcess/InjectedBundle/API/glib/WebKitInjectedBundleMain.cpp is somehow pulling on /app/webkit/WebKitBuild/deps-build/subprojects/gstreamer-full/subprojects/gstreamer/config.h instead of WebKit's config.h. This issue is somehow not happening in GTK builds...