src/Pure/Isar/proof_display.ML

  (if Config.get ctxt Proof_Context.debug then
     Pretty.quote (Pretty.big_list "proof context:" (Proof_Context.pretty_context ctxt))
   else Pretty.str "<context>");
 
 fun default_context mk_thy =
-  (case Context.thread_data () of
+  (case Context.get_generic_context () of
     SOME (Context.Proof ctxt) => ctxt
   | SOME (Context.Theory thy) =>
       (case try Syntax.init_pretty_global thy of
         SOME ctxt => ctxt
       | NONE => Syntax.init_pretty_global (mk_thy ()))