[Libreoffice] (real) Windows build, needs help.

I've been trying to build master on Windows with MSVC, and could use some help.

Multiple git pull -r, and multiple clean builds over the past several
days, and my build always fails in desktop with the following message:

(lots of WARN prior to this similar to the one below)

/cygdrive/c/libo/core-master/desktop/Executable_unopkg.mk:41:
[ WARN   ] !!!
[ WARN   ] !!! desktop/win32/source/extendloaderenvironment is linked
in by  Executable/soffice.exe Executable/unopkg.exe
[ WARN   ] !!!
[ build DEP ] SRS:deployment/res
[ build SRS ] deployment/res
[ build DEP ] SRS:deploymentgui/res
[ build SRS ] deploymentgui/res
[ build DEP ] SRS:dkt/res
[ build SRS ] dkt/res
[ build LNK ] Executable/soffice_bin.exe
C:/libo/core-master/solenv/gbuild/Package.mk:33: ***
gb_Deliver_deliver: file does not exist in solver, and cannot be
delivered: /cygdrive/c/libo/core-master/solver/wntmsci12.pro/bin/soffice_bin.exe.manifest.
 Stop.

Anyone has any clue off the top of your head as to what could be going
wrong here?

TIA,

Kohei