Solution 1:
To use passwd in single-user mode or otherwise make changes to accounts on the system, you need to load Open Directory.
launchctl load /System/Library/LaunchDaemons/com.apple.opendirectoryd.plist
To use passwd in single-user mode or otherwise make changes to accounts on the system, you need to load Open Directory.
launchctl load /System/Library/LaunchDaemons/com.apple.opendirectoryd.plist