Hi,

I have a bug in my program.
I wanted to step through the computation with ocamldebug.
Since there are some abstract data types, I have defined some printers and took advantage of the "install_printer"
mechanism provided by "ocamldebug".

What surprised me was that the printers are invoked in some cases but not always.

The attached files represent the most simplest scenario that replicate the problem.

When I start debugging:

  make
  ocamldebug main

the installed printers work as expected.

  rlwrap ocamldebug main
	OCaml Debugger version 4.08.1

  Executing file .ocamldebug
  Loading program... done.
  Time: 449
  Program exit.
  Breakpoint 1 at 158840: file main.ml, line 2, characters 3-53
  Time: 0
  Beginning of program.
  Time: 221 - pc: 158840 - module Main
  Breakpoint: 1
  2   <|b|>let _value = Aux.Submodule.value in
  File ./aux.cmo loaded
  (ocd) next
  Time: 222 - pc: 158860 - module Main
  3   <|b|>Aux.debug ()
  (ocd) p _value
  _value: Aux.Submodule.t = DEBUG: Aux.Submodule.pp

However, when I decent from one module to another, the printer no longer seems to be installed:

  (ocd) step
  Time: 223 - pc: 158668 - module Aux
  20   <|b|>let _value = Submodule.value in
  (ocd) next
  Time: 224 - pc: 158680 - module Aux
  21   <|b|>()
  (ocd) print _value
  _value: Submodule.t = <abstr>
  (ocd) install_printer Aux.Submodule.pp
  (ocd) print _value
  _value: Submodule.t = <abstr>

Above, I would expect to see

  _value: Aux.Submodule.t = DEBUG: Aux.Submodule.pp

Why do I see

  _value: Submodule.t = <abstr>

instead?

Is this an expected behavior?
What am I missing?

I always see

  <abstr>

even when I try reinstall the relevant printer:

  (ocd) install_printer Aux.Submodule.pp
  (ocd) print _value

Thank you in advance for any hints,

Cordially,
--
Matej Kosik