Signature help broken and/or missing in Neovim

[kevin-hanselman]

Issue Prelude

Please complete these steps and check these boxes (by putting an x inside the brackets) before filing your issue:

• [x] I have read and understood YCM's CONTRIBUTING document.
• [x] I have read and understood YCM's CODE_OF_CONDUCT document.
• [x] I have read and understood YCM's README, especially the Frequently Asked Questions section.
• [x] I have searched YCM's issue tracker to find issues similar to the one I'm about to report and couldn't find an answer to my problem. (Example Google search.)
• [x] If filing a bug report, I have included the output of vim --version.
• [x] If filing a bug report, I have included the output of :YcmDebugInfo.
• [x] If filing a bug report, I have attached the contents of the logfiles using the :YcmToggleLogs command.
• [x] If filing a bug report, I have included which OS (including specific OS version) I am using.
• [x] If filing a bug report, I have included a minimal test case that reproduces my issue, using vim -Nu /path/to/YCM/vimrc_ycm_minimal, including what I expected to happen and what actually happened.
• [n/a] If filing a installation failure report, I have included the entire output of install.py (or cmake/make/ninja) including its invocation
• [x] I understand this is an open-source project staffed by volunteers and that any help I receive is a selfless, heartfelt gift of their free time. I know I am not entitled to anything and will be polite and courteous.
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Issue Details

Summary

I recently saw (from reading the YCM README) that YCM added a "signature help" feature which is enabled by default. This surprised me because I program daily in Python and Go, which both support the signature help feature (according to the README), but I have never seen the signature help pop-up. I thought this might be a neovim issue, so I tried vim; sure enough, signature help works fine in vim. Is this a known deficiency with neovim?

Provide a clear description of the problem, including the following key questions:

• What did you do?

1. nvim -Nu /path/to/YCM/ycm_vimrc_minimal
2. :edit test.py
3. Enter insert mode and type:

   import time
   time.strptime(

• What did you expect to happen?

I expected to see the signature help appear for the time.striptime Python function. I confirmed the signature help appears as expected when using vim instead of nvim in the steps to reproduce above.

• What actually happened?

No signature help appeared in neovim.

Diagnostic data

Output of vim --version

$ nvim --version
NVIM v0.4.3
Build type: Release
LuaJIT 2.0.5
Compilation: /usr/bin/cc -march=x86-64 -mtune=generic -O2 -pipe -fno-plt -O2 -DNDEBUG -DMIN_LOG_LEVEL=3 -Wall -Wextra -pedantic -Wno-unused-parameter -Wstrict-prototypes -std=gnu99 -Wshadow -Wconversion -Wmissing-prototypes -Wimplicit-fallthrough -Wvla -fstack-protector-strong -fdiagnostics-color=always -DINCLUDE_GENERATED_DECLARATIONS -D_GNU_SOURCE -DNVIM_MSGPACK_HAS_FLOAT32 -DNVIM_UNIBI_HAS_VAR_FROM -I/build/neovim/src/build/config -I/build/neovim/src/neovim-0.4.3/src -I/usr/include -I/build/neovim/src/build/src/nvim/auto -I/build/neovim/src/build/include
Compiled by builduser

Features: +acl +iconv +tui
See ":help feature-compile"

   system vimrc file: "$VIM/sysinit.vim"
  fall-back for $VIM: "/usr/share/nvim"

Run :checkhealth for more info

$ pacman -Qi neovim
Name            : neovim
Version         : 0.4.3-3
Build Date      : Tue 31 Mar 2020 06:23:02 AM EDT
Install Date    : Sat 04 Apr 2020 12:20:48 PM EDT
# (can provide full output if requested)

Output of YcmDebugInfo

Printing YouCompleteMe debug information...                                                                
-- Completion API: 1
-- Client logfile: /tmp/ycm_04a0smhg.log
-- Server Python interpreter: /usr/bin/python3
-- Server Python version: 3.8.3
-- Server has Clang support compiled in: False
-- Clang version: None
-- No extra configuration file found
-- Python completer debug information:
--   Python interpreter: /usr/bin/python3
--   Python root: /home/kevin
--   Python path: ['/usr/lib/python38.zip', '/usr/lib/python3.8', '/usr/lib/python3.8/lib-dynload', '/usr/lib/python3
.8/site-packages']
--   Python version: 3.8.3
--   Jedi version: 0.17.0
--   Parso version: 0.7.0
-- Server running at: http://127.0.0.1:52465
-- Server process ID: 48114
-- Server logfiles:
--   /tmp/ycmd_52465_stdout_rv5blsp3.log
--   /tmp/ycmd_52465_stderr_dyy4o8o4.log

Output of YcmDiags

No warnings or errors detected.

Output of git rev-parse HEAD in YouCompleteMe installation directory

170bae7975de1ca3e291b535a5230dcdb46ae274

Contents of YCM, ycmd and completion engine logfiles

Reproduce the issue with vim -Nu /path/to/YCM/vimrc_ycm_minimal, which enabled debug logging and other useful diagnostics. Include a link to a gist containing all of the log files listed by :YcmToggleLogs.

https://gist.github.com/kevlar1818/4db75d2bb3fa5f535c2a24e7bb08acc0

OS version, distribution, etc.

Arch Linux (recently updated at the time of posting)

Output of build/install commands

n/a

Include link to a gist containing the invocation and entire output of install.py if reporting an installation issue.

[kevin-hanselman]

I swear I searched the issues for a good while before posting this, but somehow I missed issue #3598. My apologies. I'm really at a loss to how I missed that. I must've spent 20 minutes scouring the issue board for this issue.