Dear OCaml users,

The release of OCaml version 4.06.0 is imminent -- ideally we are
hoping for a final release by the end of October. We have created
a first beta for your testing pleasure. Please test your favourite
software with it, and let us know whether it works for you.

We want to know about any bugs, especially in the compilation and
installation phases.

This beta version is available as opam switches of the form
4.06.0+beta1 (for the default switch), and 4.06.0+beta1+feature for
feature switches (+flambda, +fp...).

    opam install 4.06.0+beta1

It is also available as source code archives at this address:

  http://caml.inria.fr/pub/distrib/ocaml-4.06/

The Changes with respect to the 4.05.0 release are available at

  http://caml.inria.fr/pub/distrib/ocaml-4.06/notes/Changes.4.06.0+beta1.txt

(We would also like to know about any backward-incompatible change
that affects you and is not explicitly marked in the Changes.)

One notable change of the upcoming 4.06.0 release is that
the -safe-string compile-time option is now activated by default:
(immutable) string and (mutable) bytes are incompatible types. It is
still possible to call the compiler with -unsafe-string, but for
this beta release we expect a large number of packages to have to be
adapted to the change. To ease your testing, if your dependencies
are affected, we have provided a 4.06.0+beta1+default-unsafe-string
switch with the old behavior.
Of course, we hope that most users will be able to adapt their
programs in time for the final release: after all, -safe-string was
introduced in OCaml 4.02.0, release on August 29th, 2014.

Note that there also exists an opam 4.06.0+trunk switch that, at any
point in time, points to the head of the 4.06.0 release branch. If
you find a 4.06.0+beta1 issue and wonder if it was already fixed
upstream, you may test using this switch (or its
4.06.0+trunk+feature siblings).

Happy hacking,

-- Gabriel Scherer and Damien Doligez for the OCaml team.