Missing loadable libraries when running pg_upgrade 9.2 -> 9.3 due to json_enhancements

In on OSX and I upgraded homebrew which upgraded me to postgres 9.3.
Now postgres won’t start because the old database is no longer compatible.
I found some promising instructions here:
http://blog.55minutes.com/2013/09/postgresql-93-brew-upgrade/

But I get stuck on running this:
pg_upgrade -d /usr/local/var/postgres -D /usr/local/var/postgres9.3 -b /usr/local/Cellar/postgresql/9.2.2/bin/ -B /usr/local/Cellar/postgresql/9.3.4/bin/ -v

(
output here: http://www.peterbe.com/pg_upgrade.log
log here: http://www.peterbe.com/pg_upgrade_server.log
)

The content of loadable_libraries.txt is this::
Could not load library "$libdir/json_enhancements"
ERROR: could not access file "$libdir/json_enhancements": No such file or directory

Yes, I had json_enhancement installed when I was using postgres 9.2. But I don’t need that any more in 9.3 because json_enhancements was a backport for 9.2.
The file is still there: /usr/local/Cellar/postgresql/9.2.2/lib/json_enhancements.so

So, I can’t upgrade because I don’t have json_enhancements installed in 9.3. Which is not possible.
And I can’t upgrade by deleting ./lib/json_enhancements.so ./share/postgresql/extension/json_enhancements--1.0.0.sql and ./share/postgresql/extension/json_enhancements.control

How to get out of this pickle?

By the way, the database that I think I have it installed on is a database I can do without. But I can’t simply `dropdb a_database_with_json_enhancements_installed` because dropdb doesn’t work any more of course.

--
Peter Bengtsson
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