Ltac2_plugin.Tac2bt
val backtrace : Tac2expr.backtrace Exninfo.t
val get_backtrace : Tac2expr.backtrace Proofview.tactic
val with_frame : Tac2expr.frame -> 'a Proofview.tactic -> 'a Proofview.tactic
val pr_frame_hook : (Tac2expr.frame -> Pp.t) Hook.t