Output from debugInfo() can't be seen in Vim 8.2

[ulidtko]

Description

Using the latest release 0.1.158 in vanilla Vim 8.2, the output from :call LanguageClient#debugInfo() "blinks" and vanishes instantly. It can be recalled with g<, but is absent from :messages.

In NeoVim however, debugInfo() works as expected.

Environment

• neovim/vim version (nvim --version or vim --version):

  • VIM - Vi IMproved 8.2 (2019 Dec 12, compiled Sep 07 2020 21:40:38)
    Included patches: 1-1634
    Compiled by Arch Linux
    

  • NVIM v0.4.4
    Build type: Release
    LuaJIT 2.0.5
    

• This plugin version (git rev-parse --short HEAD):

  $ git describe --long --tags HEAD
  0.1.158-0-g0e5c954
  

• This plugin's binary version (bin/languageclient --version): languageclient 0.1.158

To Reproduce

Steps to reproduce the behavior:

• Open Vim 8.2
• :call LanguageClient#debugInfo()

Current behavior

The output blinks very briefly and vanishes

Expected behavior

Like in NeoVim, a "Press ENTER"-style message is shown.

[ulidtko]

Together with https://github.com/redhat-developer/yaml-language-server/issues/314 which doesn't provide pretty much any debuggability tools — made me furious.

Then I realized that I've been testing in vim all the time, and in nvim it's much better.