There is no "problem" per se. It's just that Ubuntu's version of `xvfb-run` is not really compatible/consistent with the one in other distros. Some distros have deprecated `--auto-servernum` in favor of a different setting `--auto-display` which I guess does something "better". I'm just saying that Ubuntu's package could be updated to be more in-line with others.
There is no "problem" per se. It's just that Ubuntu's version of `xvfb-run` is not really compatible/ consistent with the one in other distros. Some distros have deprecated `--auto-servernum` in favor of a different setting `--auto-display` which I guess does something "better". I'm just saying that Ubuntu's package could be updated to be more in-line with others.