I checked the log comments for apm-create.sql, and it appears that section_name was shortened from 2000 to 200 after the alpha 2 release. The error message must be referring to the unique constaint which creates an index on section_name, parameter_name, and package_key, and the index exceeds the maximum key length of 1578. I'm going to try checking out one of their stable branches and see if that works any better.
