ocaml-lsp has dropped support for .merlin files

[b0o]

This issue is related to the development of the rescript-vscode /analysis sub-project, not the end use of this plugin.

Vendored modules are not being picked up by the latest version of ocamllsp, leading the LSP to display "Unbound module" errors e.g. where the Json module is used in FindFiles.ml.

From this changelog entry for ocamllsp:

Breaking Change: ocamllsp drops support for .merlin files, and as a consequence no longer depends on dot-merlin-reader. (#523)

Downgrading to ocamllsp version 1.8.3 works around this issue, but it would be nice to have support for the latest version of ocamllsp.

[cristianoc]

Thanks @b0o.
This should take care of it: #340

[jboillot]

Hello,
It may be interesting for future readers to add that ocamllsp has added an option --fallback-read-dot-merlin if you're not using dune. Note that you still need to create an empty dune-project file at the root (cf ocaml/ocaml-lsp#859 ).
This way you don't have to downgrade.

[cristianoc]

The project has been using dune for a while now.