Macports Clang 3.9 compilation failures due to missing <atomic> include

[Mojca Miklavec]

On 28 September 2017 at 16:57, Chris Jones <jonesc at hep.phy.cam.ac.uk> wrote:
> Hi,
>
> Thanks. In fact I tried adding
>
> PortGroup           cxx11 1.1
>
> but that gave me the error below. Presumably I am missiong something else ?
>
>   clang: error: invalid library name in argument
> '-stdlib=macports-libstdc++'

This means that the compiler is missing the necessary patch
(introduced by Marcus).

You need the variant +libstdcxx and clang-4.0 has that one enabled by
default, while 3.9 doesn't.

Mojca