BUG #14455: pg_upgrade fails with error

The following bug has been logged on the website:

Bug reference: 14455
Logged by: k z
Email address: kzheng1(at)gmail(dot)com
PostgreSQL version: 9.6.1
Operating system: mac OS siera
Description:

Trying to run the following command:
/usr/local/Cellar/postgresql/9.6.1/bin/pg_upgrade -d /usr/local/var/postgres
-D /usr/local/var/postgres9.6 -b /usr/local/Cellar/postgresql/9.5.4_1/bin -B
/usr/local/Cellar/postgresql/9.6.1/bin -v

Got the error in pg_upgrade_server.log

----------------------------------------------------------------
pg_upgrade run on Wed Dec 7 22:31:37 2016
-----------------------------------------------------------------

command: "/usr/local/Cellar/postgresql/9.5.4_1/bin/pg_ctl" -w -l
"pg_upgrade_server.log" -D "/usr/local/var/postgres" -o "-p 50432 -b -c
listen_addresses='' -c unix_socket_permissions=0700 -c
unix_socket_directories='/usr/local/Cellar/postgresql/9.6.1/bin'" start >>
"pg_upgrade_server.log" 2>&1
waiting for server to start....FATAL: XX000: could not load library
"/usr/local/lib/postgresql/pg_stat_statements.so":
dlopen(/usr/local/lib/postgresql/pg_stat_statements.so, 10): Symbol not
found: _GetNamedLWLockTranche
Referenced from: /usr/local/lib/postgresql/pg_stat_statements.so
Expected in: /usr/local/Cellar/postgresql/9.5.4_1/bin/postgres
in /usr/local/lib/postgresql/pg_stat_statements.so
LOCATION: internal_load_library, dfmgr.c:235
stopped waiting
pg_ctl: could not start server
Examine the log output.

kzheng1(at)gmail(dot)com writes:
> command: "/usr/local/Cellar/postgresql/9.5.4_1/bin/pg_ctl" -w -l
> "pg_upgrade_server.log" -D "/usr/local/var/postgres" -o "-p 50432 -b -c
> listen_addresses='' -c unix_socket_permissions=0700 -c
> unix_socket_directories='/usr/local/Cellar/postgresql/9.6.1/bin'" start >>
> "pg_upgrade_server.log" 2>&1
> waiting for server to start....FATAL: XX000: could not load library
> "/usr/local/lib/postgresql/pg_stat_statements.so":
> dlopen(/usr/local/lib/postgresql/pg_stat_statements.so, 10): Symbol not
> found: _GetNamedLWLockTranche
> Referenced from: /usr/local/lib/postgresql/pg_stat_statements.so
> Expected in: /usr/local/Cellar/postgresql/9.5.4_1/bin/postgres
> in /usr/local/lib/postgresql/pg_stat_statements.so

You're trying to load a 9.6 version of pg_stat_statements.so into a 9.5
server. That's not going to work. (The error message isn't too
transparent, agreed, but we have no real control over that :-(.)

I'd venture that the problem is that you've tried to use /usr/local/lib/
rather than a version-specific library directory for this extension.
It'd be smart to rethink that. In the short run you might be able to
work around it by turning off pg_stat_statements in the config for the
old server.

regards, tom lane