Build error (macOS 10.13.6)

[dboris]

# opam-version 1.2.2
# os           darwin
# command      make all
# path         /Users/boris/.opam/ocsigen/build/ppx_tools.5.1+4.06.0+multicore-1
# compiler     4.06.1
# exit-code    2
# env-file     /Users/boris/.opam/ocsigen/build/ppx_tools.5.1+4.06.0+multicore-1/ppx_tools-78621-541445.env
# stdout-file  /Users/boris/.opam/ocsigen/build/ppx_tools.5.1+4.06.0+multicore-1/ppx_tools-78621-541445.out
# stderr-file  /Users/boris/.opam/ocsigen/build/ppx_tools.5.1+4.06.0+multicore-1/ppx_tools-78621-541445.err
### stdout ###
# ocamlc -bin-annot -w +A-4-17-44-45 -I +compiler-libs -safe-string -c ast_convenience.mli
# ocamlc -bin-annot -w +A-4-17-44-45 -I +compiler-libs -safe-string -c ast_convenience.ml
# ocamlc -bin-annot -w +A-4-17-44-45 -I +compiler-libs -safe-string -c ast_mapper_class.mli
### stderr ###
# File "ast_mapper_class.mli", line 26, characters 31-49:
# Error: Unbound type constructor effect_constructor
# make: *** [ast_mapper_class.cmi] Error 2```

[hhugo]

The important bit here is that you're trying to use some version of ocaml multicore. Ocaml multicore is still WIP and won't be supported by many ocaml libraries. Try again without multicore and things should work

[dboris]

This is in a fresh switch of OCaml 4.06.1. I have installed in the past 4.02.2+multicore, but I don't think there is a multicore 4.06.1.

[hhugo]

The log you've attached mentions multicore /Users/boris/.opam/ocsigen/build/ppx_tools.5.1+4.06.0+multicore-1

[dboris]

$ opam install ocsigen-start
The following actions will be performed:
  ∗  install ppx_tools                     5.1+4.06.0+multicore-1  [required by eliom]
  ∗  install ppx_deriving                  4.2.1                   [required by eliom]

Should I file a bug report with eliom?

[dboris]

Workaround was to install a specific, non-multicore version of ppx_tools manually, before installing ocsigen-start. I guess the multicore version was considered as latest by opam, which is unaware of multicore compatibility. Not sure if the issue should be addressed by eliom, opam, or the ppx_tools maintainers.

[hhugo]

I suspect you have something non standard in your opam remote. Try opam remote list.

[dboris]

$ opam remote list
  10 [git]    multicore     https://github.com/ocamllabs/multicore-opam.git
   0 [http]     default     https://opam.ocaml.org

You are right. That must be it. Closing.

[hhugo]

Possibly related issue https://github.com/ocamllabs/multicore-opam/issues/10