On Mon, 2017-04-10 at 11:41 +0200, Toebs Douglass wrote: > > It won't use the latest and greatest version of mpfr etc for each > > compiler release, but it'll use the version that most builds of that > > release were built with, and keep you out of the weeds covering rarely > > trodden paths. > > Hmm. That is interesting. Is it then that GCC builds *normally* use > the oldest possible working version of the dependency libraries? The official GCC builds, and all distribution builds that I'm aware of, use the versions specified by that script. In fact, the very newest versions of these libraries often don't work with GCC (put another way, GCC has not been updated to work with the newest versions of these libraries). I believe that GCC has used the same versions of these libraries at least from 4.9.x through 6.x (the latest I've tried). I can't speak to whether or not they are missing out on improvements or not, but if you're trying to duplicate the GCC that everyone is using then you want to run the download_prerequisites script; it's definitely maintained. In fact this is what both https://gcc.gnu.org/install/index.html and https://gcc.gnu.org/wiki/InstallingGCC recommend.
