module Sys_open_patch: sig .. end
This module is here to avoid holding the runtime lock when doing an
    open_in_gen lock. This has been upstreamed as a patch in 3.12.1.
This module exists only to workaround some undesirable behavior in
    the function caml_sys_open in the ocaml runtime.  Delete this
    module in favor of the same functions in Pervasives once the
    runtime is patched to our satisfaction
val open_in_gen : Pervasives.open_flag list -> int -> string -> Pervasives.in_channel
Reimplementation of Pervasives.open_in_gen
val open_out_gen : Pervasives.open_flag list -> int -> string -> Pervasives.out_channel
Reimplementation of Pervasives.open_out_gen