Nixpkgs: Neovim Segmentation Fault

[iclanzan]

Describe the bug
Neovim crashes when resizing windows under some circumstances.

To Reproduce
There are many different ways to repro, these are some reliable steps to reproduce the behavior:

1. nvim -u NORC
2. Press <C-W> S to create a split
3. :te to open a terminal
4. <C-W> J to go to other window
5. <C-W> _ to maximize window

Expected behavior
Windows should resize and there should be no crash.

Additional context
Originally filed at https://github.com/neovim/neovim/issues/11458 but it seems to only be affecting NixOS. The crashes only started since I upgraded from NixOS _19.03_ to _19.09_.

Metadata

• system: "x86_64-linux"
  
  
  
  • host os: Linux 5.3.9, NixOS, 20.03pre-git (Markhor)
  
  
  • multi-user?: yes
  
  
  • sandbox: yes
  
  
  • version: nix-env (Nix) 2.3.1
  
  
  • channels(root): "nixos"
  
  
  • nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos
  
  

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute: neovim
# a list of nixos modules affected by the problem
module: applications/editors/neovim/default.nix

cc @rvolosatovs @manveru

[timokau]

If you have a known-good nixos revision and a known-bad nixos revision you could try bisecting the issue.

[jonas-schievink]

The earliest local generation on which this happens is from 2019-10-29. The latest known-good generation is from 2019-10-11. I'm not sure these are accurate though, I'd have expected this to have happened later.

[iclanzan]

git bisect narrowed it down to https://github.com/NixOS/nixpkgs/commit/53502fce1b9123b676f2722b2960bab30340b5ab which was part of https://github.com/NixOS/nixpkgs/pull/68882.

[timokau]

That looks helpful. Maybe you can report upstream that the libvterm update is responsible, and ask if someone on non-nixos can reproduce it with that version of libvterm (or report which version they use).

[iclanzan]

Thanks for guiding me in the right path @timokau, I opened a PR with a fix. :point_up:

[timokau]

Thanks for fixing this :)