Sorry for late response.
I was away from keyboard for a long time.

From: Frederick Bruckman <fredb@immanent.net>
Subject: Re: mozilla - "make" stops.
Date: Fri, 16 Aug 2002 05:32:45 -0500 (CDT)

> Maybe. You can always add a swap *file* to see if that helps. My
> Quadra 840AV, 128mb, 140mb swap is choking before it gets to the
> install stage, and it's not even touching the swap.

I think MAXDSIZ and MAXSSIZ in sys/arch/mac68k/include/vmparam.h is
too small to build mozilla.
Increse them and "ulimit -s unlimited -d unlimited" will help you.

From: Frederick Bruckman <fredb@immanent.net>
Subject: Mozilla optimization level, again
Date: Tue, 13 Aug 2002 08:21:17 -0500 (CDT)

> Is it really necessary to build mozilla with "-01" on most ports, and
> with "-O0" on m68k? I think not. Usually, if there's a problem with
> optimization levels on one file, we'll reduce it for that one file,
> not for the whole program, and mozilla is slow enough, that every
> little bit counts.

You are right.
But mac68k is *too* slow to investigate which file(s) should be
compiled without optimize.
I tried, but I give up.

-taya