Red Hat Bugzilla – Bug 9127
crontab requires -u
Last modified: 2008-05-01 11:37:54 EDT
unlike every other unix, linux crontab requires
crontab -u to specify the user to edit, as in crontab -e -u karl
instead of just crontab -e karl.
This appears to be the POSIX-compliant behavior, which was
explicitly done by the package's author.