Description of problem:
The documentation for vixie-cron is unclear on the precise order in which environment variables are accumulated for jobs, and does not mention that certain variables cannot be set from pam_env.
Version-Release number of selected component (if applicable):
For example, from cron(5) man pages (Debian):
On the Debian GNU/Linux system, cron supports the pam_env module,
and loads the environment specified by /etc/security/pam_env.conf.
How-ever, the PAM setting do NOT override the settings described
above nor any settings in the crontab file itself. Note in particular
that if you want a PATH other than "/usr/bin:/bin", you will need to
set it in the crontab file.
For clarity the following is my analysis of the current environment generation.
For each crontab file it builds a default list of environment variables similar to the following.
It then overlays any environment variables declared in the source crontab file and then sets the two explicit values.
When it comes to running a specific job from a particular crontab file it calls the routine to read the pam environment, it then overlays the environment list built for the crontab above, and then when it finally execs the requested binary it provides this environment for the command.
This request was evaluated by Red Hat Product Management for
inclusion in the current release of Red Hat Enterprise Linux.
Because the affected component is not scheduled to be updated in the
current release, Red Hat is unfortunately unable to address this
request at this time. Red Hat invites you to ask your support
representative to propose this request, if appropriate and relevant,
in the next release of Red Hat Enterprise Linux.
I'm not sure if this bug is only about documentation and if it is, what should be changed there. The problem might be fixed by errata for bug #541189.
Feel free to re-open this bug report if you are not satisfied with current release.