Feature request: support including third-party (opam or elsewhere) dependencies on jengaroot

[chenglou]

I'd like to be able to use e.g. YoJson in my jengaroot. Some of our metadata files are in json.

cc @diml

[ghost]

We are currently looking at this as we are looking into building our public packages with jenga. In the meantine a workaround is to rebuild jenga with an embed YoJson; you can do that by adding yojson there and there.

[vramana]

I have tried this workaround about but stuck with this error

*** jenga: [11392] root=/home/vramana/Documents/reasonml/exampleProject, sys=Linux, j=7, f=2 (NO_VERSION_UTIL)
*** jenga: reading node_modules/rebel/jenga.conf (rebel)
*** jenga: ERROR: Plugin failed: (src/ocaml_dynloader.ml.Dynlink_error
 "error loading shared library: /tmp/ocaml_plugin_0cf334.build/m_dyn_0_.cmxs: undefined symbol: camlYojson") 
*** jenga: ERROR: .jengaroot: User-code load failed
*** jenga: (src/ocaml_dynloader.ml.Dynlink_error"error loading shared library: /tmp/ocaml_plugin_0cf334.build/m_dyn_0_.cmxs: undefined symbol: camlYojson")
*** jenga: 0/2 targets are up to date
*** jenga: failed (#1, 0ms, heap=204.312m, stat=35, digest=1, ls=1, db-save=0)
*** jenga: todo: 0 (0 / 2) !1 ~1 j=0+0 con=2 save=0 act=0, finished
*** jenga: ERROR: (summary) .jengaroot: User-code load failed
*** jenga: (src/ocaml_dynloader.ml.Dynlink_error"error loading shared library: /tmp/ocaml_plugin_0cf334.build/m_dyn_0_.cmxs: undefined symbol: camlYojson")
*** jenga: build finished; not in polling mode so quitting
*** jenga: Quit; exit_code = 1

[ghost]

I don't have much time to debug this at the moment, but one another approach you could try is to build a jenga with the rules statically linked in. We have an example with the Jane Street rules here.

Essentially you need to write a .ml file containing:

open Core.Std
module J = Jenga_lib

let root_markers =
  [ ".git"
  ; ".hg"
  ]
  |> List.map ~f:J.Path.Rel.create

let () =
  J.Cli.main () ~run:(fun config ->
    let root_dir =
      J.Special_paths.find_ancestor_directory_containing
        ~one_of:root_markers
      |> ok_exn
    in
    J.Run.main' ~root_dir (Env Jenga_rules.Root.setup) config)

and compile it as a normal program. Jenga_rules.Root is the module containing the rules.

[vramana]

Thanks for the quick reply. I can understand the above code snippet but I don't know how I can use it with https://github.com/reasonml/rebel I will try to think some more about it.

Documenation around jenga is extremely scarce. If I have more questions, where I can ask them?

[ghost]

I guess you would need to replace Jenga_rules.Root by Rebel and link the Rebel module in.

You can ask jenga questions on the jenga project on github or on the ocaml-core@googlegroups.com mailing list