When ActiveRecord unit tests are tested with PostgreSQL v9.1.2(hstore installed),
Always got a failure as follows.
$ ARCONN=postgresql ruby -Itest test/cases/schema_dumper_test.rb -n 'test_schema_dump_includes_hstores_shorthand_definition'
Run options: -n test_schema_dump_includes_hstores_shorthand_definition --seed 31050
# Running tests:
Finished tests in 1.178730s, 0.8484 tests/s, 1.6967 assertions/s.
Expected /t.hstore "hash_store", default => ""/ to match "# ... snip ...
The dump file output is slightly different from current test code.
You can see the whole (very long) output via https://gist.github.com/1b0444910e7d6ad5b404
Address the dump file format for hstore