Fix README.md

[ohenley]

1

The actual does not build because https://opam.ocaml.org/packages/ppx_hardcaml/ indicates:
ppx_hardcaml version 1.3.0 (latest)
...
Published Sep 26, 2017

If we try anyway...

$ opam install ppx_hardcaml
[ERROR] Package conflict!
  * No agreement on the version of ocaml:
    - (invariant) → ocaml-base-compiler = 4.14.0 → ocaml = 4.14.0
    - ppx_hardcaml → hardcaml < 2.0.0 → ocaml < 4.08.0
    You can temporarily relax the switch invariant with `--update-invariant'
  * No agreement on the version of ocaml-base-compiler:
    - (invariant) → ocaml-base-compiler = 4.14.0
    - ppx_hardcaml → ppx_driver < v0.10.0 → ocaml < 4.03 → ocaml-base-compiler = 3.10.2
  * Missing dependency:
    - ppx_hardcaml → ppx_driver < v0.10.0 → ocaml < 4.03 → ocaml-variants >= 3.10.2 → ocaml-beta
    unmet availability conditions: 'enable-ocaml-beta-repository'

Now digging a bit on deps. we can see that https://opam.ocaml.org/packages/hardcaml_waveterm/
depends on ppx_deriving_hardcaml>=v0.16 & <v0.17
which fits with releases at https://github.com/janestreet/ppx_hardcaml ... which in turn is the true endpoint of ppx_deriving_hardcaml homepage.

2

The presence of $ in the copied snippet is annoying at paste in cmd

[andrewray]

Oh, this is an issue. The docs are correct for the new version, where we have renamed ppx_deriving_hardcaml to ppx_hardcaml.

However, the version story is a problem as this now clashes with the old ppx_hardcaml from Xavier, and unfortunately it has a higher version number than us.

We are going to have to rethink something here.