Tests Still Fail with mpc/mpfr linking incorrectly

[Jonathan Wakely]

On 6 October 2017 at 04:43, nick wrote:
> Greetings All,
>
> Seems I needed to use the download script for the prerequisites. Check in the docs you
> clearly hint at this but this should be updated to you need to build gcc this way. I
> and a lot of people will probably may get confused by this.
>
> Anyhow I get this now for one of the mpfr tests and searched around, there is very
> little documentation on this and how to link the libraries properly for a build.
>
>  ERROR! The versions of gmp.h (6.1) and libgmp (6.1.2) do not match.
> The possible causes are:
> * A bad configuration in your include/library search paths.
> * An inconsistency in the include/library search paths of
>   your development environment; an example:
>   http://gcc.gnu.org/ml/gcc-help/2010-11/msg00359.html
>   * GMP has been upgraded after the first "make check".
>     In such a case, try again after a "make clean".
> * A new or non-standard version naming is used in GMP.
>   In this case, a patch may already be available on the
>   MPFR web site.  Otherwise please report the problem.
>   In the first two cases, this may lead to errors, in particular with MPFR.
>   If some other tests fail, please solve that problem first.
>   FAIL tversion (exit status: 1)
>
> The only thing I was able to find was this which seems like a workaround rather than an actual fix:
> https://github.com/JuliaLang/julia/issues/6527
>
> What is the actual fix to gcc linking to my system's mpfr rather it's own internal one as this
> is breaking the tester.There is nothing at least from my scanning of the FAQ for installing
> gcc from source that explains this problem other than a few flags, what is the easiest way
> to fix this?

Do exactly what it says in https://gcc.gnu.org/wiki/InstallingGCC and
not something close, or something you believe to be similar, or
something you believe to be better.

If you do what it says there it will Just Work.