[Buildroot] [autobuild.buildroot.net] Your build results for 2017-01-13

[Jörg Krause]

Hi,

On Sat, 2017-01-14 at 08:29 +0100, Thomas Petazzoni wrote:
> Hello,
> 
> This is the list of Buildroot build failures that occured on
> 2017-01-13, and for which you are a registered architecture developer
> or package developer. Please help us improving the quality of
> Buildroot by investigating those build failures and sending patches
> to
> fix them. Thanks!
> 
> Build failures related to your packages:
> 
>          arm |                       mpd-0.20 | http://autobuild.buil
> droot.net/results/da259e57f96cf0dd6fbac9fe44826e93f986d9e9
>        sparc |                       mpd-0.20 | http://autobuild.buil
> droot.net/results/242b4cff0257f353ce6b2df744c51488dbc0d2c5
>        sparc |                       mpd-0.20 | http://autobuild.buil
> droot.net/results/8d50a025ffcc5b3408fa27f59f0cd896616dc2c6
>         i686 |                       mpd-0.20 | http://autobuild.buil
> droot.net/results/362233e40960f8f0410bf24404fa05ce38cbfb56
>        nios2 |                       mpd-0.20 | http://autobuild.buil
> droot.net/results/a5506440bd02726d6e3b0240ece876c73b92b546
>        sparc |                       mpd-0.20 | http://autobuild.buil
> droot.net/results/e964b1f0ac39ec9c14f5e3b368132d8dc671c249
> 

The error message is:

error: 'exception_ptr' in namespace 'std' does not name a type

The problem is related to this bug report [1]. Both std::future and
std::exception_prt are only enabled in libstdc++ if
'ATOMIC_INT_LOCK_FREE > 1'. std::exception_prt is only supported for
targets with always-lock-free atomics for int. This is a long-standing
issue in the libstdc++ and was finally fixed in GCC trunk r244051
[2][3] and will be available in GCC 7.0.

Any suggestions how to handle this build error?

1) Disable for the targets concerned and wait for GCC 7.0?
2) Backport the patch?

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64735
[2] https://gcc.gnu.org/viewcvs/gcc/trunk/libstdc%2B%2B-v3/include/std/
future?view=log&pathrev=244051
[3] https://github.com/gcc-mirror/gcc/commit/c45be7f1aef92f2ea7363cbc46
27f943b83ca902

Best regards,
Jörg Krause