Checking out multiple times breaks about solidus-demo HOT 1 CLOSED

After looking into it, I think this is the issue:

After you check out the first time, the stock item has the changes you made to it stored as a sample change. The next time you check out, those sample changes are loaded in - but the way they are loaded in sets them as unsaved changes. And of course you can't lock something with unsaved changes, so this error happens when Solidus tries to get a lock on it.

Possible solutions:
Don't load changes for stock items
Override the method to do the same thing without getting a lock (we're not actually saving anything so it shouldn't be necessary?)
Override whatever lock method in Rails that is called to sort of "soft disable" locking - meaning locking won't actually do anything in this app (since it doesn't need to) - this might be good because this issue could exist elsewhere in more remote circumstances.

from solidus-demo.