I have tried. With your commands (added with a "screen -L -Logfile screenlog.txt") I dont get the error. I have tried a 2nd time, where I started "bash -x clonezilla" instead of your 2nd command. This resulted in screenlog2.txt. But after some testing and better understanding, I think it is by design and not a bug. If there are no existing partitions to choose as target, the restoreparts will always exit with this error.
"box" is an unkown partition device on target selection for restoreparts