Issue with install, searched gnu.org - unfortunately manual is more than 810 pages thick without instruct for install;
Plus manual pages in ubuntu is 8529+ lines (again) without straight forward instruct as to install..
Noting that to configure GCC, it must be made from a shell environment first;
% mkdir objdir % cd objdir % srcdir/configure [options] [target]
Not sure whether this is the same with distributions through package manager on ubuntu, version 4:4.8.2-1ubuntu6 (or) just releases through gnu.org - versions 5.3 (the latest).