  $ dune build @install @runtest --display short
         ocaml config.full
      ocamldep src/.plop.eobjs/plop.ml.d
      ocamldep src/.plop.eobjs/config.ml.d
        ocamlc src/.plop.eobjs/byte/config.{cmi,cmo,cmt}
        ocamlc src/.plop.eobjs/byte/plop.{cmi,cmo,cmt}
      ocamlopt src/.plop.eobjs/native/config.{cmx,o}
      ocamlopt src/.plop.eobjs/native/plop.{cmx,o}
      ocamlopt src/plop.exe

This example creates a configuration file using a fallback rule.
See README.org for details

By default, config is set:

  $ dune exec ./src/plop.exe
  Built with support for blah: true
  Path to blah is:             "/path/to/blah"

Print generated config:

  $ cat _build/default/config.full
  
  let with_blah = true
  let blah_path = "/path/to/blah"

Now, we disable it, and re-run:

  $ echo "let enable_blah = No" > config
  $ dune exec ./src/plop.exe
  Built with support for blah: false
  Path to blah is:             "<no support for blah>"
  $ cat _build/default/config.full
  
  let with_blah = false
  let blah_path = "<no support for blah>"

Remove --display short from config example
Remove --display short from config example

Signed-off-by: Rudi Grinberg <b1c1d8736f20db3fb6c1c66bb1455ed43909f0d8@rgrinberg.com>
