This module implements loading the jengaroot (whose type is defined in jenga_root_interface.ml) using ocaml_plugin.
module Spec : sig ... end
A description of what files are to be loaded, ie what is the "jengaroot" exactly.
val get_env : Spec.t ‑> [ `Env of Env.t | `Toplevel_exn of Core.Exn.t ] Core.Or_error.t Async.Deferred.t