Couple of templates that can be used to repro or debug active record issues. You'll need to install any gems first as this isn't using bundler, and this may not work across all rails versions. The general idea will work though, you may just have to figure out what needs changing between versions.
In addition to helping debug issues this is useful for submitting issues as you can have repro steps contained in a single file. Often this is nicer than submitting a stack trace with version numbers as it gives maintainers something they can run.
Running the file with --debug will set the active record logger to STDOUT and
also attempt to output a relevant calling line.