Helloworld fails to link on Debian

[Sebastien Alaiwan via D.gnu]

Just to show that my compiler is up-to-date:

$ dpkg -l | grep "gdc\|phobos"
ii  gdc                                       4:6.2.1-1           
                  amd64        D compiler (language version 2), 
based on the GCC backend
ii  gdc-6                                     6.2.1-5             
                  amd64        GNU D compiler (version 2)
ii  libgphobos-6-dev:amd64                    6.2.1-5             
                  amd64        Phobos D standard library
ii  libgphobos-dev                            6.2.1-1             
                  amd64        Phobos D standard library
ii  libgphobos68:amd64                        6.2.1-5             
                  amd64        Phobos D standard library (runtime 
library)
$ gdc --version
gdc (Debian 6.2.1-5) 6.2.1 20161124
Copyright (C) 2016 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  
There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A 
PARTICULAR PURPOSE.