denops.vim: Failing to connect to denops server

Recently I keep getting [denops] Failed to connect denops server: Failed to connect 127.0.0.1:port error messages and autocomplete stops working. Here’s the full message after :let g:denops#debug = 1 | call denops#server#restart():

[denops] Server spawned: ['deno', 'run', '-q', '--no-check', '--unstable', '-A', '/Users/ldavis/dotfiles/.vim
/plugged/denops.vim/denops/@denops-private/cli.ts', '--mode=vim']
[denops] DenopsStarted
[denops] Connecting to `127.0.0.1:53944`
[denops] Failed to connect denops server: Failed to connect `127.0.0.1:53944`
[denops] Server stopped: -1
[denops] DenopsStopped

I tried switching from deno 1.17.0 to the latest version 1.22.0 but this did nothing. I’m using macOS 12.4 (Monterey). I’ve also updated to the latest version of denops.vim with :PlugUpdate and the latest version of vim: 8.2.3901.

Anything else I can do to try to debug this? I tried manually running the command deno run -q --no-check --unstable -A /Users/ldavis/dotfiles/.vim/plugged/denops.vim/denops/@denops-private/cli.ts --mode=vim and it seems to work fine… for some reason vim is just unable to connect with ch_open… it’s really strange.

About this issue

Original URL
State: closed
Created 2 years ago
Reactions: 2
Comments: 17 (10 by maintainers)

Most upvoted comments

I think the port is used or blocked by other applications.

I’m experiencing this as well. I think @Shougo is correct that it’s being blocked. The only thing that has solved it so far is rebooting. Here are the other things I’ve tried:

Restarting Vim
Changing networks
Turning network/wifi on and off again
Running :call denops#server#restart() — This fails every time on different ports

Manually running the denops server and using :call denops#server#connect Same issue:

[denops] Failed to connect `127.0.0.1:32123`: Failed to connect `127.0.0.1:32123`

Manually running ch_open and then ch_status on 127.0.0.1:32123 while the server runs. ch_status returns fail.

I’ll continue investigating what’s blocking this connection.

stevematney on Nov 30, 2022

I didn’t test in neovim but simply restarting my macbook solved the problem. Still not sure why it happened… but hopefully this thread will be useful for someone else.

lukelbd on Jun 1, 2022

I haven’t heard related issue recently so close it. Please create a new one if you face similar issue.

lambdalisue on Oct 22, 2023

@stevematney What is your environment? I think you should test it with other environment.

@Shougo my work machine is a managed Macbook Pro with an Intel processor. I’m fairly certain it has something to do with the firewall that I can’t modify or disable, and possibly some of the VPN integration stuff. I know there’s not much I can do at the network level to isolate the issue. This is why I’d like to get to the bottom of why other plugins work and denops doesn’t. If I can find that, maybe I can figure out how to keep denops running for me.

I also have been using denops and ddc on a personal M1 Macbook Pro, and haven’t seen the same issue. It seems pretty clear that it has something to do with the setup on my other machine.

stevematney on Dec 5, 2022

It seems you accidentally set let g:denops_server_addr = '127.0.0.1:32123'? That’s for shared server feature so without using shared server, the connection will fail as expected.

I forgot to mention! This was not accidental. I wanted a consistent IP for the denops server for debugging, so I set that IP and ran the server manually. Then I tried running the connect command with the same results.

So, to be clear, the server was running while I was doing this (and it could receive commands from other processes).

stevematney on Dec 3, 2022