Never mind. I goofed. Just got a new PC and copied the cygwin dir from the old PC onto the new: that caused the Mozilla build to fail. Solution: re-installed the cygwin toolkit :)
Another problem I encountered which I recommend talking about in http://www.mozilla.org/build/win32.html: you do need a separate assembler such as the Microsoft Macro Assembler (MASM), executable name ML.EXE. Got mine at http://users.easystreet.com/jkirwan/pctools.html -- POC
