A patch to fix this issue was already committed to master.
I don’t recommend using 1.9.0 at this time, the crash is probably related to an issue that has just been fixed, but will be backported to 1.9 tree only next week (when 1.9.1 will be released).
If you want to test this patch, I suggest you stick with 1.8 for now, or wait for the releases next week (which will also contain the fix for the consistent hash redispatch issue).