If you stick the sources folder inside your user folder you can share it between multiple build envs.
I only built it in the first place to see how it was done. Then I was going to use it to build debug versions of enigma2, but decided that it wasn't really a development/debug environment, just a build one.
So I built gcc for my box (and gfortran - so I now have a working spell-checker for my editor on my box!!) However, I then realized that I didn't have autoconf/automake,
etc., so now build enigma2 in a Debian mips qemu environment in a VirtualBox Debian system, which works well enough to test things (and I have an OpenVix set-up running in a similar qemu environment - so I can compile in a multi-core, 16GB set-up)).
But now I see that OpenVix4.0 moved to gcc 5.3, so at some point I may have to look at getting everything working in that OpenVix qemu set-up...
What would be better would be to work out bit-bake recipes to get teh standard build to build mips-native versions of relevant tools along the way, but I haven't figured out how to do that, and the only such recipes for gcc I could find are part of an old bitbake set-up that is no longer in use. Perhaps I need to read the documentation....