this is only for _building_ on windows

solenv/inc/tg_ext.mk

@@ -189,7 +189,7 @@ $(PACKAGE_DIR)/$(PATCH_FLAG_FILE) : $(PACKAGE_DIR)/$(ADD_FILES_FLAG_FILE)
     @echo no patch needed...
     $(COMMAND_ECHO)$(TOUCH) $@
 .ELSE			# "$(PATCH_FILES)"=="none" ||	"$(PATCH_FILES)"==""
-.IF "$(GUI)"=="WNT"
+.IF "$(GUI_FOR_BUILD)"=="WNT"
     $(COMMAND_ECHO)cd $(PACKAGE_DIR) && $(TYPE:s/+//) $(BACK_PATH)$(PATH_IN_MODULE)/{$(PATCH_FILES)} | tr -d "\015" | patch $(PATCHFLAGS) -p2 && $(TOUCH) $(PATCH_FLAG_FILE)
 .ELSE           # "$(GUI)"=="WNT"
     $(COMMAND_ECHO)cd $(PACKAGE_DIR) && $(TYPE) $(BACK_PATH)$(PATH_IN_MODULE)/{$(PATCH_FILES)} | $(GNUPATCH) $(PATCHFLAGS) -p2 && $(TOUCH) $(PATCH_FLAG_FILE)