I did an “opam switch” to OCaml 4.07.0. All of the packages I had installed for 4.06.1 installed nicely, except “ocsigenserver”:
# File "ocsigen_server.ml", line 1326, characters 8-27:
# Warning 3: deprecated: module Lwt_chan
# Use module Lwt_io.
# File "_none_", line 1:
# Error: Files ../baselib/baselib.cma(Ocsigen_commandline)
# and ../baselib/parsecommandline.cma(Ocsigen_getcommandline)
# make inconsistent assumptions over interface Ocsigen_getcommandline