strange -fPIC compilation error

[Sebastien Alaiwan via Digitalmars-d-learn]

Hello,
 From GCC 6.2, -fpie is becoming the default setting at compile 
and at link time.
As dmd uses GCC to link, now the code needs to be compiled with a 
special option.
Which means you need, at the moment, to add the following options 
to your dmd.conf:
  -defaultlib=libphobos2.so -fPIC
(the change from GCC is related to security and address space 
randomization).