[Koha] What does this zebraidx error mean?

Greetings, Thank you to eythian and ebegin on the #koha channel. After finding the cause of our indexing problem (a 16MB /tmp partition, which we have no power to change), and using the -d parameter on the koha-rebuild-zebra script to point to a different temporary directory, I was able to get a full reindex to run to completion. I did get a strange error once while doing so, and I am wondering if this was solely because of permission problems I had on the temporary directory that I specified, or if there is something else. Here is the error: zebraidx: it_key.c:98: key_compare: Assertion `l <= 5 && l > 0' failed. Any ideas? GPML, Mark Tompsett