[Windows] Failure authenticating to Github via SSH

[jacobsheahan]

Description

Our Windows builds are consistently failing ever since updating to image version: '20250617.1.0'. Previously were working using image version: '20250609.2.0' (and number of versions before this).

Git error. Command: `git clone --mirror git@github.com:<my repo> C:\Users\VssAdministrator\AppData\Local\Pub\Cache\_temp\dir7816cfc6`
stdout: 
stderr: Cloning into bare repository 'C:\Users\VssAdministrator\AppData\Local\Pub\Cache\_temp\dir7816cfc6'...
Read from remote host github.com: Connection reset by peer
client_loop: send disconnect: Connection reset by peer
fetch-pack: unexpected disconnect while reading sideband packet
fatal: early EOF
fatal: fetch-pack: invalid index-pack output

exit code: 128

We do have a step that uses InstallSSHKey@0 task to install the SSH key. Notice that the version of the git tools was updated between the working version of runner and current version of runner.

Also note we are also building using macos-14 version '20250623.1377' and macos-13 version '20250616.1247' for iOS and Android that are working fine

Platforms affected

• Azure DevOps
• GitHub Actions - Standard Runners
• GitHub Actions - Larger Runners

Runner images affected

• Ubuntu 22.04
• Ubuntu 24.04
• macOS 13
• macOS 13 Arm64
• macOS 14
• macOS 14 Arm64
• macOS 15
• macOS 15 Arm64
• Windows Server 2019
• Windows Server 2022
• Windows Server 2025

Image version and build link

20250617.1.0'

Is it regression?

Yes; 20250609.2.0

Expected behavior

Git able to clone to authenticated repo using SSH

Actual behavior

Git error. Command: `git clone --mirror git@github.com:<my repo> C:\Users\VssAdministrator\AppData\Local\Pub\Cache\_temp\dir7816cfc6`
stdout: 
stderr: Cloning into bare repository 'C:\Users\VssAdministrator\AppData\Local\Pub\Cache\_temp\dir7816cfc6'...
Read from remote host github.com: Connection reset by peer
client_loop: send disconnect: Connection reset by peer
fetch-pack: unexpected disconnect while reading sideband packet
fatal: early EOF
fatal: fetch-pack: invalid index-pack output

exit code: 128

Repro steps

See description

[lakshminarayana02]

Hi
We are looking into this issue and will keep you updated here.

[housei]

I got around it by downgrading git.

    steps:
      - name: Install Git 2.49.0 Portable
        run: |
          $url = "https://github.com/git-for-windows/git/releases/download/v2.49.0.windows.1/PortableGit-2.49.0-64-bit.7z.exe"
          Invoke-WebRequest -Uri $url -OutFile git-portable.exe
          Start-Process -Wait -FilePath ".\git-portable.exe" -ArgumentList "-y", "-oC:\tools\git\2.49.0"
          Remove-Item -Path .\git-portable.exe -Force
          echo "C:\tools\git\2.49.0\cmd" >> $env:GITHUB_PATH

      - name: Confirm Git usage
        run: git --version

[jacobsheahan]

I got around it by downgrading git.

    steps:
      - name: Install Git 2.49.0 Portable
        run: |
          $url = "https://github.com/git-for-windows/git/releases/download/v2.49.0.windows.1/PortableGit-2.49.0-64-bit.7z.exe"
          Invoke-WebRequest -Uri $url -OutFile git-portable.exe
          Start-Process -Wait -FilePath ".\git-portable.exe" -ArgumentList "-y", "-oC:\tools\git\2.49.0"
          Remove-Item -Path .\git-portable.exe -Force
          echo "C:\tools\git\2.49.0\cmd" >> $env:GITHUB_PATH

      - name: Confirm Git usage
        run: git --version

Thanks for the suggestion - can confirm that this workaround did work for me!

[Prabhatkumar59]

Hi @jacobsheahan - Please confirm if this issue has already been resolved on your end. Thank you!"

[grzegorzkrukowski]

It's still happening today on our runners:
windows-2022-8core_bf60cf62bc36
Version: 20250617.1.0