MerlinLocate not resolving definition of core modules

[ddickstein]

If I have an OCaml file as follows:

open Core
module L = List
...

and I try to MerlinLocate on List, I get the following error:

Several source files in your path have the same name, and merlin doesn't know which is the right one:
/usr/local/lib/ocaml/list.ml, /usr/local/lib/ocaml/list.mli, /Users/dani/.opam/system/lib/core_kernel/
list.ml, /Users/dani/.opam/system/lib/core_kernel/list.mli, /Users/dani/.opam/system/lib/base/list.ml,
 /Users/dani/.opam/system/lib/base/list.mli

Why is Merlin having trouble selecting the right one? I'm using Merlin version 3.2.2.

(Following up on issue 2 in #863. The behavior I had been seeing was that this issue occurred when trying to go to definition a second time, as though the locate was cached and there was an issue with the cached version, but now the issue happens even on the first locate request)

[b0o]

@ddickstein I know this issue is really old, but did you ever figure out a solution? I am experiencing the same problem.

[ddickstein]

My understanding is that duniverse <https://github.com/avsm/duniverse>, when it arrives, will solve this problem.

…

On Thu, Aug 8, 2019 at 9:24 PM Maddison Hellstrom ***@***.***> wrote: @ddickstein <https://github.com/ddickstein> I know this issue is really old, but did you ever figure out a solution? I am experiencing the same problem. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#894?email_source=notifications&email_token=AAGD5T6EIXOHUZR3Z46YQADQDTBNBA5CNFSM4GMNQFN2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD35KLTY#issuecomment-519742927>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAGD5T66NOLGGOP4VESDUELQDTBNBANCNFSM4GMNQFNQ> .

[trefis]

I don't think "the duniverse" will help at all with this.
You have several "list.ml" in your path right now, that'll still be the case with the duniverse.

That being said, I just tried to reproduce the issue right now and wasn't able to. (Though I used Base and not Core).
There have been a lot of fixes on locate since this issue was created. And perhaps this one is fixed and @b0o is actually encountering a different problem?

[trefis]

@ddickstein: can you confirm whether you can reproduce the issue or not?

[ddickstein]

Yes, this problem is still occurring for me (using merlin 3.3.2).

I'm using dune 1.9 (set in my dune-project file), an empty dune workspace file, and my dune file itself where I'm testing the jump to definition looks like this:

(library
  (name rocket_game)
  (inline_tests)
  (libraries core sexplib)
  (preprocess (pps ppx_jane)))

I guess I was mistaken about what duniverse would fix - I was told it would fix the problem of jumping to definitions from inside opam libraries, and I assumed the difficulties merlin was having with locating the right file for the initial jump was related to the library living outside my project.

[ddickstein]

@trefis can the "Awaiting feedback" tag here be removed unless more feedback is needed?

(continues to affect latest dune + merlin)

[DouglasGray]

Just a heads up I am also seeing this. If I try to jump to:
Core.Command.Arg_type.create

I get an error saying:
"Several source files in your path have the same name, and merlin doesn't know which is the right one: /home/.../.opam/ocaml-base-compiler.4.09.0/lib/core_kernel/command.ml, /home/.../.opam/ocaml-base-compiler.4.09.0/lib/core/command.ml

My version of Merlin is 3.3.3. I am using Dune (version 2.4.0) to manage my project and .merlin file though, so not sure if it's more appropriate to chat to the Dune folk.

[ddickstein]

I created a minimal repro case as a dune issue (I'm honestly not sure which project should host this issue, since I'm trying to solve this merlin locate problem with vendoring in dune).

ocaml/dune#3971

[rgrinberg]

@DouglasGray I'm unable to reproduce your particular issue with the latest dune & merlin.