Update docs

HACKING.md

@@ -370,8 +370,8 @@ thoroughly (e.g. `git clean -dfX`) before reconfiguring with a different prefix.
 
 Then build the compiler with the command `make _install` (this is the default
 target plus some setup in preparation for installation). As usual when building,
-a 4.14 compiler (and dune and menhir) need to be in the path. See the warnings above
-about the versions of dune and menhir to use.
+a 4.14 compiler (and dune and menhir) need to be in the path. See the warning above
+about the version of and menhir to use.
 
 Now the build part is done, we don't need to stay in the build environment
 anymore; the switch creation will likely replace it if your terminal is setup

README.md

@@ -20,7 +20,7 @@ One-time setup (you can also use other 4.14.x releases):
 ```
 $ opam switch 4.14.1  # or "opam switch create 4.14.1" if you haven't got that switch already
 $ eval $(opam env)
-$ opam install dune.3.8.1 menhir.20210419
+$ opam install dune.3.15.2 menhir.20210419
 ```
 
 You probably then want to fork the `ocaml-flambda/flambda-backend` repo to your own Github org.

configure.ac

@@ -5,7 +5,7 @@ AC_INIT([The Flambda backend for OCaml],
         [flambda_backend],
         [http://github.com/ocaml-flambda/flambda_backend])
 
-DUNE_MAX_VERSION=[3.8]
+DUNE_MAX_VERSION=[3.15]
 
 AC_MSG_NOTICE([Configuring Flambda backend version AC_PACKAGE_VERSION])