compiling gcc 5.x from the scratch: issues

[Jonathan Wakely]

On 10 September 2015 at 17:23, Martin Sebor wrote:
> FWIW, I think the more common source of problems for those new
> to building GCC is not having all the right prerequisites. The
> GCC configure script tries to detect whether the right versions
> are available but does only a superficial job (checks their
> version macros) which can lead to cryptic build failures down
> the line when not all the right architectures are installed
> (e.g., the i686 in addition to x86_64). It also proceeds when
> MPC is not installed at all which then causes the build to fail.

Not having the right prerequisites certainly used to be a common
problem (not quite as common as having them but installing them
outside ld.so's search dirs and then not setting LD_LIBRARY_PATH).
However, since I've been on a crusade to stop people doing that by
pointing them at https://gcc.gnu.org/wiki/InstallingGCC and telling
them to use contrib/download_prerequisites it is *much* less common
than it used to be.

Markus, I think your patch wouldn't hurt, and might help people who
fail to read the instructions carefully, so I suggest sending it to
gcc-patches for review.