Ocamlfind does not allow -thread

Hello,

I do not know where I should post this message, if this should be 
reported to opam or ocamlfind…

I've switch my opam env from ocaml 4.02.1 to 4.02.3

After this operation, ocamlfind does not detect anymore that my system 
is thread compatible (I'm using cygwin)

$ ocamlfind ocamlopt -thread
ocamlfind: ocamlopt does not support multi-threaded programs for your 
configuration

invoking directly ocamlopt does not report errors :

$ ocamlopt -thread ; echo $?
0

invoking the previous version works also fine :

$ ~/.opam/4.02.1/bin/ocamlfind.exe  ocamlopt -thread ; echo $?
0

Is this a configuration problem ?


Thanks !