`vim-rescript` tries to use `complete`: https://github.com/rescript-lang/vim-rescript/blob/faeeb2deef1ad0ec67fc892ceeb9949f3bf2d77c/autoload/rescript.vim#L346 The underlying `rescript-editor-analysis.exe` expects `completion`: https://github.com/rescript-lang/rescript-vscode/blob/master/analysis/src/Cli.ml#L66