"More targets than List items" when testing tmux for the clipboard provider (breaks clipboard healthcheck)

[Gelio]

Neovim version (nvim -v)

v0.9.0-dev-280+gfae754073

Vim (not Nvim) behaves the same?

no, vim 8.1

Operating system/version

Ubuntu 20.04 LTS

Terminal name/version

kitty 0.26.1

$TERM environment variable

xterm-kitty

Installation

build from repo

How to reproduce the issue

1. Install tmux from source so tmux -V prints tmux next-3.4
2. DISPLAY="" nvim -c checkhealth
3. /clipboard
4. There error should be there, assuming clipboard.vim tried to parse tmux -V output

Expected behavior

Some clipboard provider is detected and there is no healthcheck error.

Actual behavior

Clipboard healthcheck ends with an error:

provider: health#provider#check
========================================================================
  - ERROR: Failed to run healthcheck for "provider" plugin. Exception:
    command line..function health#check[20]..health#provider#check[1]..<SNR>127_check_clipboard[10]..script /usr/local/share/nvim/runtime/autoload/provider/clipboard.vim[248]..function                    provider#clipboard#Executable, line 74
    Vim(let):E688: More targets than List items

The problem seems to be caused by 8172289 (#20936,

neovim/runtime/autoload/provider/clipboard.vim

Line 142 in fae7540

let [major, minor] = matchlist(systemlist(['tmux', '-V'])[0], 'tmux \(\d\+\)\.\(\d\+\)')[1:2]

). The regexp does not handle non-numeric versions, such as next-3.4.

[Gelio]

Thanks for a quick fix @gpanders ! I confirm that the bug no longer manifests itself