I am glad to announce Merlin 5.8.1-505, a new release that notably fixes a caching issue that manifested frequently when using OCaml-LSP with Dune in watch mode.
We also released preview versions of both Merlin and OCaml-LSP working with today’s OCaml compiler’s trunk. You can use them to hack on the compiler, but they will break again with futures changes to the types AST.
I love it! 
I wanted to ask if you still support the object-oriented layer. Sometimes, I really want to use this part of OCaml, but it also causes problems with DX in those tools.
We do support it, but these parts have been a bit neglected in the past and we are not heavy users of the O ourselves. Please open an issue (usually on Merlin’s github repository) when you stumble onto a DX issue !
I also fixed a bunch of object-related issues recently, I think it was part of Merlin 5.7.0-504.