fails to compile on ocaml 4.02 due to safe-string

[avsm]

+ make  (CWD=/home/opam/.opam/4.02.1/build/alberto.0.4)
- ocaml setup.ml -build 
- ocamlfind ocamlopt unix.cmxa -I /home/opam/.opam/4.02.1/lib/ocaml/ocamlbuild /home/opam/.opam/4.02.1/lib/ocaml/ocamlbuild/ocamlbuildlib.cmxa -linkpkg myocamlbuild.ml /home/opam/.opam/4.02.1/lib/ocaml/ocamlbuild/ocamlbuild.cmx -o myocamlbuild
- /home/opam/.opam/4.02.1/bin/ocamlfind ocamldep -package ocplib-endian -package num -package camlp4 -package bytes -modules src/alberto.mli > src/alberto.mli.depends
- /home/opam/.opam/4.02.1/bin/ocamlfind ocamlc -c -g -annot -bin-annot -safe-string -w @a -warn-error -a -package ocplib-endian -package num -package camlp4 -package bytes -I src -o src/alberto.cmi src/alberto.mli
- /home/opam/.opam/4.02.1/bin/ocamlfind ocamldep -syntax camlp4o -package ocplib-endian -package num -package camlp4 -package bytes -modules src/alberto.ml > src/alberto.ml.depends
- /home/opam/.opam/4.02.1/bin/ocamlfind ocamlc -c -g -annot -bin-annot -safe-string -w @a -warn-error -a -syntax camlp4o -package ocplib-endian -package num -package camlp4 -package bytes -I src -o src/alberto.cmo src/alberto.ml
- + /home/opam/.opam/4.02.1/bin/ocamlfind ocamlc -c -g -annot -bin-annot -safe-string -w @a -warn-error -a -syntax camlp4o -package ocplib-endian -package num -package camlp4 -package bytes -I src -o src/alberto.cmo src/alberto.ml
- File "src/alberto.ml", line 32, characters 16-19:
- Error: This expression has type bytes but an expression was expected of type
-          string
- Command exited with code 2.

[superbobry]

Interesting, I've failed to reproduce this locally with both 4.02.0 and 4.02.1.