ocamlfind wants to link with system packages, not just installed packeges

[Kakadu]

for example, lwt wants to link with /usr/lib/ocaml/react/, not _dep/lib/ract.

$ ocamlfind printconf
Effective configuration:
Configuration file:
    /etc/ocamlfind.conf
Search path:
    /media/disk/kakadu/prog/barbra/_dep/lib
    /home/kakadu/.odb/lib
    /usr/local/lib/ocaml/3.12.1
    /usr/lib/ocaml
    /usr/lib/ocaml/METAS
Packages will be installed in/removed from:
    /media/disk/kakadu/prog/barbra/_dep/lib
META files will be installed in/removed from:
    the corresponding package directories
The standard library is assumed to reside in:
    /usr/lib/ocaml
The ld.conf file can be found here:
    ignore