I'm all for dropping features for whatever reason. I suggest three things:
1) Remove the option from /etc/radicale/config, so people don't think they can
enable it.
2) Comment in the readme that PAM won't work for the reasons you provided. This
will stop people from relying on the upstream documentation or other tutorials
online (which say it should just work).3) Change the error message to journald
when radicale is started with PAM enabled, which currently reads "An exception
occurred during server startup: PAM authentication requires the Python pam
module", implying that PAM authentication will work with the right packages.
This is what I thought until I found this bug report. It should probably say
"PAM authentication is not supported" instead.
The benefit to you is that fewer people like me will bother you trying to
understand why it's not working (if they don't stumble upon this bug first).
I'm not sure whether an undocumented feature worse than a documented unfeature.
