Package `lwt' not found

["Yiming Zhang" <sdiris@xxxxxxxxx>]

I followed Thomas's advice and type 'opam update' and 'opam install base-unix 
cow mirage-fs'. But there still be errors as follows. 

Is it still due to the regression in 0.3? If so, how to upgrade to 0.3.1?

Thanks!
Yiming
------------------------------------------
+ /root/.opam/system/bin/ocamlfind query -r -i-format cstruct lwt lwt.unix
ocamlfind: Package `lwt' not found
make[1]: *** [all] Error 2
make: *** [all] Error 2
[2914] ERROR: Compilation failed with error 2
[2914] ERROR: Globals.Exit(66)
[2910] ERROR: Command failed while installing mirage.0.3dev
  'opam install base-unix cow mirage-fs' failed