Comment 35 for bug 278095

Once you've added the ddebs apt repo in sources.list try:

sudo apt-get install firefox-3.0-dbgsym \
     xulrunner-1.9-dbgsym \
     libgtk2.0-0-dbg \
     libnss3-1d-dbgsym \
     libnspr4-0d-dbg \
     libpango1.0-0-dbg \
     libcairo2-dbg \
     libc6-dbg

Details on:
https://wiki.ubuntu.com/MozillaTeam/Bugs