File "/home/thelema/ocamlbrew/ocaml-4.00.0/lib/ocaml/site-lib/qtest/qTest2Lib.cma(Unix)", line 1:
Warning 31: files /home/thelema/ocamlbrew/ocaml-4.00.0/lib/ocaml/site-lib/qtest/qTest2Lib.cma(Unix) and /home/thelema/ocamlbrew/ocaml-4.00.0/lib/ocaml/unix.cma(Unix) both define a module named Unix
It looks like qTest2Lib includes the unix module, and it shouldn't; the qtest package should only depend on Unix.
File "/home/thelema/ocamlbrew/ocaml-4.00.0/lib/ocaml/site-lib/qtest/qTest2Lib.cma(Unix)", line 1: Warning 31: files /home/thelema/ocamlbrew/ocaml-4.00.0/lib/ocaml/site-lib/qtest/qTest2Lib.cma(Unix) and /home/thelema/ocamlbrew/ocaml-4.00.0/lib/ocaml/unix.cma(Unix) both define a module named Unix
It looks like qTest2Lib includes the unix module, and it shouldn't; the qtest package should only depend on Unix.