How can I fully include "libdruntime-ldc.a" and "libphobos2-ldc.a" in my .so lib ?

[Basile B. via Digitalmars-d-learn]

My dub recipe includes this

  "dflags" : [
    "bin/libdruntime-ldc.a",
    "bin/libphobos2-ldc.a"
  ]
so that ideally I'll get everything in the library but this does 
not work. For example rt_init and rt_term are no visible in the 
exports

  $ nm -D libdexed-d.so | grep rt_init
  $

and the project that uses the library does not link anyway, 
unless I instruct LD to use libdruntime-ldc.so.