type OpamStd.Config.E.t += | BUILDDOC of bool option| BUILDTEST of bool option| DOWNLOADJOBS of int option| DRYRUN of bool option| IGNORECONSTRAINTS of string option| JOBS of int option| LOCKED of string option| MAKECMD of string option| NODEPEXTS of bool option| NOENVNOTICE of bool option| ROOT of string option| SWITCH of string option| UNLOCKBASE of bool option| WITHDEVSETUP of bool option| WITHDOC of bool option| WITHTEST of bool option
val root : unit -> string optionval switch : unit -> string option