Firefox is a massive application. I happened to rebuild a 6.0-stable/i386 package for firefox-esr, and noticed:
- There were 147 third party build dependencies.
- It took 3 minutes 45 seconds just to unpack the the source code tarball on solid state disk.
- The unpacked tarball consumed a gigabyte of storage.
And, since 2012, the build has used clang rather than gcc on i386.