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Marcus Summers daa771760b wiki: add WSL OpenSSH default shell + Ansible world-writable mount articles

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>

2026-04-03 10:23:02 -04:00

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Windows OpenSSH: WSL as Default Shell Breaks Remote Commands

Problem

SSH remote commands fail with:

Invalid command line argument: -c
Please use 'wsl.exe --help' to get a list of supported arguments.

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.

Cause

Windows OpenSSH's default shell is set to C:\Windows\System32\wsl.exe. When SSH executes a remote command, it invokes:

<default_shell> -c "<command>"

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.

Fix

Change the default shell to PowerShell. Run this in an elevated PowerShell on the Windows host:

New-ItemProperty -Path "HKLM:\SOFTWARE\OpenSSH" -Name DefaultShell -Value "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -PropertyType String -Force
Restart-Service sshd

If you need to run this from within WSL (e.g., over an interactive SSH session):

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'"

After the Fix

Remote SSH commands now execute via PowerShell

To run Linux commands, prefix with wsl:

ssh user@host "wsl bash -c 'cd /mnt/d/project && git pull'"

Interactive SSH sessions land in PowerShell (use wsl to enter Linux)
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

Key Notes

This registry key is the only supported way to change the OpenSSH default shell on Windows
The change persists across reboots and Windows Updates
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
Tools like Ansible, scp, rsync, and ssh-copy-id all depend on -c working

Windows OpenSSH Server (sshd) Stops After Reboot — sshd service startup issues
Microsoft Docs: OpenSSH DefaultShell

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