troubleshooting-devbox

SSH host key errors occur when the remote host's key changes or doesn't match your local cache. Remove the old key with ssh-keygen -R devbox and ssh-keygen -R $(hcloud server ip devbox), then reconnect using ssh -o StrictHostKeyChecking=accept-new devbox to accept the new key.

Verify NixOS and required services are running on the devbox using ssh devbox 'nixos-version', ssh devbox 'tmux -V', and ssh devbox 'nvim --version'. Check system errors with journalctl -b --priority=err and review active services using systemctl --user list-timers.

Run health checks to confirm environment integrity: confirm the SSH host key, verify NixOS version and tools are installed, check system logs for errors, and validate active services. Rebuild NixOS with sudo nixos-rebuild switch if needed and reboot as necessary.

NixOS recovery involves rolling back to a previous generation or rebuilding your configuration. Use journalctl to identify errors, then run sudo nixos-rebuild switch to apply the current configuration, or reboot to activate changes.

Troubleshoot SSH failures by removing stale host keys, verifying connectivity with updated key acceptance, checking NixOS system health via journalctl and systemctl, and confirming disk space and service status on the remote host.