When I execute a rake task manually, it works fine but when I put the same command in Cron nothing happens:
cd /path/to/my/rails/app && rake daily_import
The Cron log indicates that the command was issues:
CMD (cd /path/to/my/rails/app && rake daily_import)
The rake task logs error and success messages, but nothing is recorded to the log, nothing is done at all. However if I copy and paste the text of the CMD with the same user Cron is running the command in everything works fine.
I’m assuming that running a task in Cron should be the same as typing it in myself, is this correct?
Look for mail that the cron daemon might have sent to the user under which the cron job is running. If a cron job produces output on stderr or stdout, the cron daemon will email that to the owner of the cron job. If something is going wrong (possibly because of a PATH issue, like Rob suggests above), you might see a helpful error message in an email from the cron daemon.