Slam mapping won't produce a map

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I've set up ros and the gmapping node with a node I've developed to operate a laser rangefinder. I've gotten through some basic issues where the gmapping would buffer the scans, figured out I did not have proper transforms. Now when I turn on debug level logging for gmapping I get this for every scan that comes in:

[DEBUG] [1482595623.382913308]: MessageFilter [target=odom ]: Message ready in frame laser at time 1482595623.381, count now 0
[DEBUG] [1482595623.383080352]: processing scan
[DEBUG] [1482595623.383558079]: cannot process scan
[DEBUG] [1482595623.384082414]: MessageFilter [target=odom ]: Added message in frame laser at time 1482595623.381, count now 0

I've looked through the source code and it appears there are a couple reasons this could happen but I'm at a loss to figure out what is happening.

Thanks for any pointers.