shared memory deadlock between git commands launched in same shell

[ConceptualWempa]

• [✓] I was not able to find an open or closed issue matching what I'm seeing

Setup

• Which version of Git for Windows are you using? Is it 32-bit or 64-bit?

64-bit

$ git --version --build-options

git --version --build-options
git version 2.47.0.windows.2
cpu: x86_64
built from commit: 1f8a83c
sizeof-long: 4
sizeof-size_t: 8
shell-path: D:/git-sdk-64-build-installers/usr/bin/sh
feature: fsmonitor--daemon
libcurl: 8.10.1
OpenSSL: OpenSSL 3.2.3 3 Sep 2024
zlib: 1.3.1

• Which version of Windows are you running? Vista, 7, 8, 10? Is it 32-bit or 64-bit?

10, 64-bit

$ cmd.exe /c ver

Microsoft Windows [Version 10.0.19045.5011]

• What options did you set as part of the installation? Or did you choose the
  defaults?

defaults, except default branch name

One of the following:

type "C:\Program Files\Git\etc\install-options.txt"
type "C:\Program Files (x86)\Git\etc\install-options.txt"
type "%USERPROFILE%\AppData\Local\Programs\Git\etc\install-options.txt"
type "$env:USERPROFILE\AppData\Local\Programs\Git\etc\install-options.txt"
$ cat /etc/install-options.txt

cat /etc/install-options.txt
Editor Option: VIM
Custom Editor Path:
Default Branch Option: main
Path Option: Cmd
SSH Option: OpenSSH
Tortoise Option: false
CURL Option: OpenSSL
CRLF Option: CRLFCommitAsIs
Bash Terminal Option: MinTTY
Git Pull Behavior Option: Merge
Use Credential Manager: Enabled
Performance Tweaks FSCache: Enabled
Enable Symlinks: Disabled
Enable FSMonitor: Disabled

• Any other interesting things about your environment that might be related
  to the issue you're seeing?

None that I'm aware of.

Details

• Which terminal/shell are you running Git from? e.g Bash/CMD/PowerShell/other

Git Bash

• What commands did you run to trigger this issue? If you can provide a
  Minimal, Complete, and Verifiable example
  this will help us understand the issue.

git gui &
git log

• What did you expect to occur after running these commands?

git log should've printed usual output

• What actually happened instead?

git log hangs with no output ... upon ctrl-c, something similar to follow is printed:

  0 [] less 2283 C:\Program Files\Git\usr\bin\less.exe: *** fatal error - Can't reopen shared memory during exec, Win32 error 6

• If the problem was occurring with a specific repository, can you provide the URL to that repository to help us with testing?

does not appear to be related to a specific repo ... although, perhaps significantly, 'git init ...' in the same shell does NOT hang, and 'git log' in the resulting empty workspace prints:
fatal: your current branch 'main' does not have any commits yet
as expected ... 'git status' and 'git add' also work, but 'git commit' hangs and ctrl-c elicits similar output (except the program reported is ...\usr\bin\sh.exe)

[dscho]

Hmm. I cannot reproduce. In a freshly-initialized worktree:

$ git gui &
[3] 2215

$  git log
fatal: your current branch 'main' does not have any commits yet

[ConceptualWempa]

@dscho try with a non-empty repo - I saw the same result with an empty one while experimenting, suppose I should've specified that "the usual output" meant at least one commit, i.e. a non-empty repo.