If you run configure just with --enable-wayland-target then the X11
target is disabled unless you make it explicit (see bug 121703).
In this case the build fails because all the methods added to
PluginPackageNone.cpp in r159999 (see bug 123997) are already defined
in PluginPackage.cpp, e.g
Source/WebCore/plugins/PluginPackageNone.cpp:72: multiple definition of `_ZN7WebCore13PluginPackageD1Ev'
Source/WebCore/plugins/.libs/libWebCore_la-PluginPackage.o:Source/WebCore/plugins/PluginPackage.cpp:41: first defined here
Žan also reported this one.
*** This bug has been marked as a duplicate of bug 126927 ***