Force the recording of backtraces

src/import.ml

@@ -6,6 +6,9 @@ module Set     = MoreLabels.Set
 
 external reraise : exn -> _ = "%reraise"
 
+(* To make bug reports usable *)
+let () = Printexc.record_backtrace true
+
 let open_in = open_in_bin
 let open_out = open_out_bin
 

src/main.ml

@@ -88,7 +88,7 @@ let report_error ?(map_fname=fun x->x) ppf exn ~backtrace =
       pkg
   | Code_error msg ->
     let bt = Printexc.raw_backtrace_to_string backtrace in
-    Format.fprintf ppf "@{<error>Internal error, please report upstream.@}\n\
+    Format.fprintf ppf "@{<error>Internal error, please report upstream (include the contents of _build/log.@}\n\
                         Description: %s\n\
                         Backtrace:\n\
                         %s" msg bt