Re: Crosscompiling C++ for powerpc64le fails

["Ludovic Courtès" <ludo@gnu.org>]

Hi Danny,

Danny Milosavljevic <dannym@scratchpost.org> skribis:

> I've investigated a bit more:
>
> Guix's gcc-4.7 passes
>
>   (string-append "--with-native-system-header-dir=" libc "/include")
>   where libc is (assoc-ref %build-inputs "libc")
>
> .
>
> However, further down, there is
>
>                 `(let* ((libc        (assoc-ref %build-inputs "libc"))
>                        (libc-native (or (assoc-ref %build-inputs "libc-native")
>                                         libc)))
>
>
> which makes me think that "--with-native-system-header-dir=" should use
> libc-native if the latter is present.
>
> It would be possible to pass "--with-headers=" to gcc which would make it copy
> the specified directory into the gcc installation directory and everything
> would work without weird workarounds.

You’re probably right, it would be worth giving it a try.

The weird thing is that:

  guix build mpfr --target=arm-linux-gnueabihf

works fine on current master, which uses GCC 5.5 for cross-compilation.

The issue that Tobias reports reminds me of the CPATH vs. C_INCLUDE_PATH
issue that was causing troubles with newer GCCs, and that I think Marius
addressed in ‘core-updates’ (?).  Marius, does that ring a bell?

Thanks,
Ludo’.