compilation issue

[campiador]

On OSX, ocaml 4.06.01 and ruby 2.5.1p57, I face the following error trying to make redexer.

$ make

ocamlbuild -use-ocamlfind main.native

• ocamlfind ocamlopt -c -package sha,str,unix,ppx_deriving.std,ppx_deriving_yojson,yojson -I src -I ocamlutil -I src/ext -o src/util.cmx src/util.ml
  File "src/util.ml", line 108, characters 15-23:
  Warning 3: deprecated: S.create
  Use Bytes.create instead.
  File "src/util.ml", line 111, characters 16-31:
  Warning 3: deprecated: String.set
  Use Bytes.set instead.
  File "src/util.ml", line 124, characters 8-51:
  Error: This expression has type bytes list
  but an expression was expected of type string list
  Type bytes is not compatible with type string
  Command exited with code 2.
  Compilation unsuccessful after building 27 targets (0 cached) in 00:00:02.
  make: *** [main.native] Error 10

This error probably has to do with strings being mutable by default before ocaml version 4.06. So for the time being a workaround is switching back to ocaml version 4.02.2:

opam init --comp 4.02.2
opam switch 4.02.2