When attempting to use pg_journal on Fedora 27, PostgreSQL fails to start throwing an error about a missing symbol in pg_journal.so: postgresql-ctl[14009]: FATAL: could not load library "/usr/lib64/pgsql/pg_journal.so": /usr/lib64/pgsql/pg_journal.so: undefined symbol: sd_journal_sendv
pg_journal-0.2.0-19.fc27 has been submitted as an update to Fedora 27. https://bodhi.fedoraproject.org/updates/FEDORA-2017-28fd6d82e8
pg_journal-0.2.0-19.fc27 has been pushed to the Fedora 27 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2017-28fd6d82e8
pg_journal-0.2.0-19.fc27 has been pushed to the Fedora 27 stable repository. If problems still persist, please make note of it in this bug report.