В этой нет ничего нового

oscam 11503 does not include the emu. It just includes some basic changes that the emu reader needs, but not the actual reader. You still have to patch with the emu reader, or use the already patched oscam-emu from github.

oscam 11503 can understand what an emu reader is though. So, if you build oscam svn 11503 with the WITH_EMU option enabled, but without patching with the actual emu, you will get an a dummy emu reader that does nothing.

If you compile oscam svn 11503 with the WITH_EMU option disabled, then you will get the message above, since oscam does not know what an emu reader is and what config options it uses.