Avoid 'assert false' when looking up module .cmo

[Julow]

This error was reachable when also hitting this error:

Error: Error: Inferred type of injected ident not found. You need to
       regenerate services/.services.objs/byte/game.cmo.

[Julow]

Also, I'm hitting this error while trying to move .eliom and dune files into a subdirectory. Any idea how I could troubleshoot this error?

[vouillon]

We have rules like:

(rule (target wup_page.ml) (deps ../wup_page.eliom)
  (action
    (with-stdout-to %{target}
      (chdir .. (run tools/eliom_ppx_client.exe --as-pp -server-cmo %{cmo:../wup_page} --impl wup_page.eliom)))))

Is it possible that the dependency on %{cmo:../wup_page} (the server-side cmo file) is missing in your case?

[Julow]

Thanks for the help! The rule that generates the error is this one:

(rule (target game.ml) (deps ../services/game.eliom)
  (action
    (with-stdout-to %{target}
      (chdir .. (run ../tools/eliom_ppx_client.exe --as-pp -server-cmo %{cmo:../services/game} --impl %{deps})))))

That %{cmo:...} is substituted with a correct path. The invocation is like this, perhaps the PPX doesn't like the directory structure ?

$ (cd _build/default/src && ../tools/eliom_ppx_client.exe --as-pp -server-cmo services/.services.objs/byte/game.cmo --impl services/game.eliom) > _build/default/src/client/game.ml

[vouillon]

Maybe the issue is that eliom_ppx_client and eliom_ppx_server are called with different file path? We are hashing the whole file name to generate unique ids, but we should probably hash just the base file name. https://github.com/ocsigen/eliom/blob/b264bf98e9e96354f19e6623ce4135367c362e13/src/ppx/ppx_eliom_utils.ml#L53