My build completed successfully! (I forgot to credit gemal.dk's website with some very good instructions. One piece of advice: read the problems he lists and implement the solutions he suggests before attempting a build. I have no doubt this saved me some heartache.) I'm writing this comment from it.
That said, I am already getting extremely sick of these NS_ASSERTION alerts. Abort, Retry, Ignore options appear every time I hit one. It's from here.
Fortunately, dmose already answered my question here.
Rule of thumb for MinGW builders of Mozilla: read both the Windows and the Linux FAQs. They will both apply (and surprisingly enough, don't directly contradict each other that much).
Posted by WeirdAl at January 8, 2005 10:50 AM