Before you submit bug reports: https://vdirsyncer.pimutils.org/en/stable/contributing.html

Things to include in your bugreport:

* Your vdirsyncer version
* If applicable, which server software (and which version) you're using
* Your Python version
* Your operating system
* Your config file
* Use `vdirsyncer -vdebug` for debug output. The output is sensitive, but
  please attach at least the last few lines before the error (if applicable),
  censored as necessary. This is almost always the most useful information.
