Cannot link with libphobos2.a with GCC 6.2 on Ubuntu 16.10

[Nordlöw via Digitalmars-d-learn]

On Thursday, 13 October 2016 at 19:11:36 UTC, Adam D. Ruppe wrote:
> Try `-defaultlib=libphobos2.so` with your dmd command line. The 
> .so version is pic compiled.

Building DMD fails to how do I modify the call

     make -f posix.mak

under the dmd checkout?