Marcus Summers
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Two new troubleshooting articles from today's MajorRig/MajorMac Ansible setup: - Windows OpenSSH WSL default shell breaks remote SSH commands - Ansible silently ignores ansible.cfg on WSL2 world-writable mounts Article count: 76 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
70 lines
2.8 KiB
Markdown
70 lines
2.8 KiB
Markdown
---
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title: "Windows OpenSSH: WSL as Default Shell Breaks Remote Commands"
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domain: troubleshooting
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category: networking
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tags: [windows, openssh, wsl, ssh, majorrig, powershell]
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status: published
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created: 2026-04-03
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updated: 2026-04-03
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---
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# Windows OpenSSH: WSL as Default Shell Breaks Remote Commands
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## Problem
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SSH remote commands fail with:
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```
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Invalid command line argument: -c
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Please use 'wsl.exe --help' to get a list of supported arguments.
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```
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This happens on **every** remote command — `ssh-copy-id`, `ssh user@host "command"`, `scp`, etc. Interactive SSH (no command) may still work if it drops into WSL.
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## Cause
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Windows OpenSSH's default shell is set to `C:\Windows\System32\wsl.exe`. When SSH executes a remote command, it invokes:
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```
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<default_shell> -c "<command>"
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```
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But `wsl.exe` does not accept the `-c` flag. It expects `-e` for command execution, or no flags for an interactive session. Since OpenSSH hardcodes `-c`, every remote command fails.
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## Fix
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Change the default shell to PowerShell. Run this in an **elevated PowerShell** on the Windows host:
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```powershell
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New-ItemProperty -Path "HKLM:\SOFTWARE\OpenSSH" -Name DefaultShell -Value "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -PropertyType String -Force
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Restart-Service sshd
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```
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If you need to run this from within WSL (e.g., over an interactive SSH session):
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```bash
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powershell.exe -Command "Start-Process powershell -Verb RunAs -ArgumentList '-Command New-ItemProperty -Path HKLM:\\SOFTWARE\\OpenSSH -Name DefaultShell -Value C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\powershell.exe -PropertyType String -Force; Restart-Service sshd'"
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```
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## After the Fix
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- Remote SSH commands now execute via PowerShell
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- To run Linux commands, prefix with `wsl`:
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```bash
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ssh user@host "wsl bash -c 'cd /mnt/d/project && git pull'"
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```
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- Interactive SSH sessions land in PowerShell (use `wsl` to enter Linux)
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- `ssh-copy-id` still won't work for WSL's `authorized_keys` — Windows OpenSSH reads from `C:\Users\<user>\.ssh\authorized_keys`, not the WSL home directory
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## Key Notes
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- This registry key is the **only** supported way to change the OpenSSH default shell on Windows
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- The change persists across reboots and Windows Updates
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- If you previously set the default shell to `wsl.exe` to get a Linux-first SSH experience, be aware that it permanently breaks all remote command execution
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- Tools like Ansible, `scp`, `rsync`, and `ssh-copy-id` all depend on `-c` working
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## Related
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- [Windows OpenSSH Server (sshd) Stops After Reboot](windows-sshd-stops-after-reboot.md) — sshd service startup issues
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- [Microsoft Docs: OpenSSH DefaultShell](https://learn.microsoft.com/en-us/windows-server/administration/openssh/openssh-server-configuration#configuring-the-default-shell-for-openssh-in-windows)
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