[BUG] `git stash` exits without output when lockfile present

What did you do before the bug happened? (Steps to reproduce your issue)

In clean repo root:

$ touch foo
$ touch .git/index.lock
$ git stash

What did you expect to happen? (Expected behavior)

An error message to stderr explaining that .git/index.lock exists, etc.

What happened instead? (Actual behavior)

`git stash` has an exit code of 1, with no output on stdout or stderr.

What's different between what you expected and what actually happened?

I didn't notice at first that the stash failed, and I was briefly 
confused. I guess I've never tried to stash and gotten this error 
before, but whenever I see the "lockfile exists" error I feel like the 
UX is very consistent with other commands. I expected stash to work the 
same way.

I apologize if this is a dupe, I don't know how to search the archives.


[System Info]
git version:
git version 2.34.1
cpu: x86_64
no commit associated with this build
sizeof-long: 8
sizeof-size_t: 8
shell-path: /bin/sh
uname: Linux 5.19.16-76051916-generic 
#202210150742~1666053244~22.04~cf07008 SMP PREEMPT_DYNAMIC Tue O x86_64
compiler info: gnuc: 11.2
libc info: glibc: 2.35
$SHELL (typically, interactive shell): /bin/zsh


[Enabled Hooks]