Error on install with neovim-0.9

[bonderado]

Description

⚠️ All issues without an minimal init.vim or instructions to reproduce can be automatically closed.

When first starting neovim with a init.vim that uses dein, the automatic call to dein#remote_plugins() emits an error message and the remote plugins are not configured.
Calling dein#remote_plugins() manually afterwards does not configure the plugins either, although no error message is displayed.

To Reproduce

Steps to reproduce the behavior:

1. Delete the plugins directory
2. Start neovim with the minimal init.vim provided below
3. See error
   Errore/i eseguendo VimEnter Autocommands for "*"..function dein#remote_plugins[1]..dein#install#_remote_plugins:
   riga 26:
   E730: uso di Lista come Stringa
   Premi INVIO o un comando per proseguire

Expected behavior

No error message, the installation completes and remote plugins are configured..

Desktop:

• OS: Linux 6.1.0-5-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.12-1 (2023-02-15) x86_64 GNU/Linux
• Vim or Neovim version: NVIM v0.9.0-dev-1092+gbc15b075d
• Dein Commit: b16c2ca

Minimal Config

if &compatible
  set nocompatible
endif
let $XDG_VIM_PLUGINS=expand("$HOME/.cache/nvim/plugins")
let $PLUGIN_MANAGER=expand("$XDG_VIM_PLUGINS/repos/github.com/Shougo/dein.vim")
echom $XDG_VIM_PLUGINS
echom $PLUGIN_MANAGER
call mkdir($XDG_VIM_PLUGINS, "p", 0755)
set runtimepath+=$PLUGIN_MANAGER

if empty(glob("$PLUGIN_MANAGER/.git"))
      execute "!git clone https://github.com/Shougo/dein.vim $PLUGIN_MANAGER"
endif

if dein#load_state($XDG_VIM_PLUGINS)

  call dein#begin($XDG_VIM_PLUGINS)
  " call dein#add(expand('$PLUGIN_MANAGER'))

  call dein#add('Shougo/dein.vim')
    call dein#add('Shougo/deoplete.nvim')
      call dein#end()
  call dein#save_state()
endif

filetype plugin indent on
syntax enable

if dein#check_install()
     call dein#install()
endif

Additional context

I started noticing the issue with the stock NVIM v0.7.2 x on my debian (the still seems to work with dein overall): there I do not get the error message, but the plugins are still not configured. Since the latest dein requires newer version, I installed an appimage of the latest prerelease, that is used for this bug report, as noted in the Desktop section.

[Shougo]

Reproduced.

[Shougo]

Fixed. Please update.