Debugging an mcron job

[Jack Hill <jackhill@jackhill.us>]

[-- Attachment #1: Type: text/plain, Size: 1591 bytes --]

Hi Guix,

I'm looking for help or tips on debugging an mcron job. My goal is to run 
a site-specific telemetry script that I have packaged [0] in my channel. 
The script collects some information and sends it to a remote server. I am 
trying to run the script as an mcron job via a service I created in my 
channel [1].

[0] https://gitlab.oit.duke.edu/jackhill/guix-at-duke/blob/0ed0a8e7530ef32b9e268d43b36944e38defa5f1/guix-at-duke/packages/endpoint-management.scm#L98-140
[1] https://gitlab.oit.duke.edu/jackhill/guix-at-duke/blob/0ed0a8e7530ef32b9e268d43b36944e38defa5f1/guix-at-duke/services/endpoint-management.scm

So far, this looks good, and after pulling my channel, reconfiguring, and 
restarting mcron, I can see my job in herd schedule mcron:

"""
# herd schedule mcron
Tue Mar 12 00:51:00 2019 -0400
/gnu/store/61692zjpkhy3jqv4a7jk1k8a14k6yn8k-planisphere-report-0-0.1b606af/bin/planisphere-report
…
"""

However, this doesn't appear to work because after the appointed time, the 
remote server is not updated. If I run the planisphere-report command by 
hand, the remote server is updated.

If I replace the planisphere-report command in my job with 
"/run/current-system/profile/bin/touch /tmp/test-file", test-file is 
indeed touched, so I know that the jobs are running.

Being fairly new to Guix, and extremely new to mcron, I don't know how to 
debug further. Are jobs run in such a way that they don't have network 
access? How can I see any errors or output?

Best,
Jack

P.S. I'm happy to accept any comments about how to improve the code in my 
channel as well ☺.