I can reproduce the bug on the master branch with the following steps:
1. Apply 0001-XXX-Dirty-hack-to-clobber-control-file-for-testing.patch [1] 2. Compile PostgreSQL with `-DEXEC_BACKEND` C compiler flag option. 3. Run `initdb` 4. Run `postgres` 5. Run `pgbench -i` 6. Run `psql -c 'do $$ begin loop perform pg_update_control_file(); end loop; end; $$;'`
7. Run `for run in {1..5000}; do pgbench -c50 -t100 -j6 -S postgres; done` in parallel with the previous command.
