When I tried a full rebuild of svn 12878, I had a problem in spellcheker, at line 36 in HunspellInterface.h :
hunspell.h is not found.
Nevertheless this file is here in ...\SpellChecker\hunspell\src\hunspell and the search path to compile HunspellInterface.cpp seems to be correct.
May be something strange is that in HunspellInterface.cpp you have :
#include "hunspell.h"
#include "HunspellInterface.h"
but HunspellInterface.h contains itself an #include "hunspell.h"
I have solved this by making a copy (in fact, creating hardlinks) of hunspell.h and hunvisapi.h directly in main spellchecker directory. But, it's just a workaround.
PS: I have not this problem with svn 12877.