opam-build can not find target project batsh

[mthl]

Hello,

I am trying to compile Batsh to hack on it, however I fail to build it. after installing the dependencies with opam install ocp-build core ounit dlist cmdliner the make command fails with the following error

$ make
ocp-build build batsh
Compiler: ocaml 4.05.0
Warning: 36 old env warnings were not printed (add --env-warnings)
Warning: installed package "threads" has conflicting directories:
   first: threads@/home/mthl/.opam/4.05.0/lib/ocaml
     (from /home/mthl/.opam/4.05.0/lib/threads/META)
   second: threads@/home/mthl/.opam/4.05.0/lib/ocaml/threads
     (from /tmp/Batsh/src/batsh.ocp)
Use the --disable-package PKG@DIR to disable one of them.
Choosing "threads".
Warning: 9 old project warnings were not printed (add --project-warnings)
Error: Could not find target project batsh
Makefile:2: recipe for target 'build' failed
make: *** [build] Error 2

Any idea what the issue is?