I don't have time to evaluate and respond to all your points, but your
first entry under "frightening discoveries" really jumped out at me. On
line 499:

try closed_type ty with Non_closed (ty0, real) ->

The name "ty0" is a pattern capture variable, which the pattern matching
construct binds to the first argument of the caught exn value with
constructor Non_closed. It doesn't need a prior declaration... you are
declaring it right there. Surely you were simply mistaken? I find it
unbelievable that someone could write OCaml for years, even hacking on the
compiler, without understanding basic pattern matching.


On Thu, Jan 16, 2014 at 3:00 PM, Jürgen Pfitzenmaier <
pfitzen@pfitzenmaier.de> wrote:

>   Dear Ocaml users,
>  I found some serious errors in the compiler e.g. in line 28 of typing/
> includecore.ml
>  and line 499 of typing/ctype.ml of version 3.12.1.
>
>  A longer list of errors with explanations and possible fixes will be
> under
>        www.pfitzenmaier.de/ocaml-considered-dangerous.html
>
>  regards,
>  Jürgen
>
>