BUG #13461: Error message appears to use incorrect values

The following bug has been logged on the website:

Bug reference:      13461
Logged by:          Kevin Martin
Email address:      martin.kevin@gmail.com
PostgreSQL version: 9.4.1
Operating system:   AWS RDS
Description:

Given a column of 1000-dimension cubes the following triggers an error:
CREATE INDEX ktest ON items USING gist(embeddings);
ERROR:  index row size 8016 exceeds maximum 8152 for index "ktest"

The error message appears to be out of order - the index row size reported
is smaller than the maximum.