Any attempt to use the PostgreSQL 10beta1 client library (whether via psql, PGDG-provided psycopg2-2.7 or anything else using libpq) with valid Kerberos ticket to 9.5/9.6 servers fails.
Taking "psql -h <server> <database>" as a test: Expected behaviour: (same as 9.6 client) successful connection to the server. Actual behaviour: "*** Error in `psql': free(): invalid pointer: 0x00007f9d0e105fbc ***" reported on terminal, program aborts.
