Stdout is Missing When Executed as Subprocess

[chengzhuo5]

• 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?

$ git --version --build-options
git version 2.44.0.windows.1
cpu: x86_64
built from commit: ad0bbfffa543db6979717be96df630d3e5741331
sizeof-long: 4
sizeof-size_t: 8
shell-path: /bin/sh
feature: fsmonitor--daemon
** insert your machine's response here **

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

$ cmd.exe /c ver

Microsoft Windows [Version 10.0.26090.112]

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

# 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

Editor Option: VisualStudioCode
Custom Editor Path:
Default Branch Option:
Path Option: Cmd
SSH Option: OpenSSH
Tortoise Option: false
CURL Option: OpenSSL
CRLF Option: LFOnly
Bash Terminal Option: ConHost
Git Pull Behavior Option: Merge
Use Credential Manager: Enabled
Performance Tweaks FSCache: Enabled
Enable Symlinks: Enabled
Enable Pseudo Console Support: Enabled
Enable FSMonitor: Enabled

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

No

Details

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

PowerShell

I'm encountering an issue when executing Git as a subprocess, where I'm unable to receive any output.

Here's the code that fails to produce output:

const { exec, execSync, spawn } = require('child_process');
exec('git.exe --version', (error, stdout, stderr) => {
  console.log(error, stdout, stderr); // null, '', ''
});
execSync('git.exe --version', {
  stdio: 'pipe',
});

However, the following code does produce output:

execSync('git.exe --version', {
  stdio: 'inherit',
});

This issue is not specific to Node.js. I’ve encountered the same problem when executing Git as a subprocess using other languages like TCL/TK.

This issue is causing nearly all Git plugins to fail, including the official Git-Gui.

Any help or guidance on this issue would be greatly appreciated.

[dscho]

const { exec, execSync, spawn } = require('child_process');
exec('git.exe --version', (error, stdout, stderr) => {
console.log(error, stdout, stderr); // null, '', ''
});
execSync('git.exe --version', {
stdio: 'pipe',
});

You did not really say it, but this is a Node.js script.

It does work on my machine, though:

PS C:\me> node --version
v20.10.0
PS C:\me> node a1.js
null git version 2.44.0.windows.1

[chengzhuo5]

const { exec, execSync, spawn } = require('child_process');
exec('git.exe --version', (error, stdout, stderr) => {
console.log(error, stdout, stderr); // null, '', ''
});
execSync('git.exe --version', {
stdio: 'pipe',
});

You did not really say it, but this is a Node.js script.

It does work on my machine, though:

PS C:\me> node --version
v20.10.0
PS C:\me> node a1.js
null git version 2.44.0.windows.1

What is your Windows version? I tried it on both Win11 22621 and 26090 versions, neither worked.

[chengzhuo5]

Well, I reinstalled Windows and it worked. I will continue to search for the cause of the problem. This issue is closed first.

[chengzhuo5]

After I installed the isolated domain software (DACS) provided by my company, the issue recurred. I have reported this issue to the author of DACS and will continue to follow up on this issue.

[chengzhuo5]

I found that the Windows Filtering Platform driver provided by the security software seems to have changed the buffer type of stdout from _IONBF to _IOFBF or _IOLBF, causing stdout to fail without manually calling fflush(stdout) when the buffer is not full. The contents of the output buffer. I will file a PR to manually call fflush(stdout) when git exits.

[chengzhuo5]

#4901

[dscho]

/add relnote bug Apparently some anti-malware programs fiddle with the mode of stdout which can lead to problems because expected output is missing, which was fixed.

The workflow run was started