Fails on Spacemacs + Windows + Cygwin

[mindbound]

I have all of the following:

• Windows 10 Pro x64;
• Cygwin 64-bit, fully updated;
• GNU Emacs 25.3.1 via https://sourceforge.net/projects/emacsbinw64;
• Spacemacs 0.200.9 from official repo master, with ocaml layer, fully updated;
• OCaml 4.02.3+mingw64c, manually installed via https://fdopen.github.io/opam-repository-mingw/;
• depext 1.0.5, depext-cygwinports 0.0.6, merlin 2.5.5, ocamlfind 1.7.3, yojson 1.4.0 via opam install.

Emacs is being run via C:\cygwin\usr\local\bin\ocaml-env-win.exe -- "C:\\emacs\bin\\emacsclientw.exe" --alternate-editor="C:\\emacs\\bin\\runemacs.exe" -c in order to have all variables automatically set up. When opening an .ml file (either new or existing) and trying to write in it, each key press that invokes merlin fails (writes the character but throws an error in the messages buffer and fails to actually call merlin functionality) with

Company: An error occurred in auto-begin Company: backend merlin-company-backend error "merlin: error (end-of-file) trying to parse answer: " with args (candidates le)

where le is the current word I'm writing. Reinstalling any or all of the above components has no effect on the issue. Additionally, merlin works normally when using Atom or Visual Studio Code with the appropriate extensions.

[let-def]

Can you try with the git version of merlin (opam pin add merlin --dev-repo)? I am not sure if this will work with fdopen repository, in any case a new release of merlin for windows is long overdue, I will try to make it soon. Sorry for that.

[mindbound]

I can upgrade merlin to the git version just fine but it still fails with the same error.