shockvalue@Precept:~$ compiz --replace -c emerald
/usr/bin/compiz.real (core) - Error: Another window manager is already running on screen: 0
/usr/bin/compiz.real (core) - Error: Another window manager is already running on screen: 1
/usr/bin/compiz.real (core) - Fatal: No manageable screens found on display :0.0