XScreenSaver: Reporting Bugs

If any part of the XScreenSaver collection appears to have a bug, I need as much information as possible about what went wrong. Please describe the problem in as much detail as you can. I'll also need to know:

macOS, iOS and Android users:

Which screen saver is it?
What is the XScreenSaver version number? (very important!)
What is the macOS or iOS version number, and/or iPhone/iPad model?
Have you tried the latest version of XScreenSaver to see if your bug is already fixed?

If using macOS, please do the following:

Open Terminal.app;
Type this:
egrep 'Saver|Pref' /var/log/system.log
Mail me everything that was printed.
If the "Library/Logs/CrashReporter" folder (under your home directory) contains files for "ScreenSaverEngine" or "System Preferences", include those as well.

If a particular option setting is making one of the screen savers crash, you can reset the options to the default state by deleting the corresponding file in "Library/Preferences/ByHost/". The file name will begin with "org.jwz.xscreensaver.SaverName".

X11 users:

Have you read the FAQ?
Which screen saver(s) exhibit the problem?
What is the XScreenSaver version number? (very important!)
(Don't just say something like "The version that came with Fedora 4". I don't necessarily know what version that is.)
Have you tried the latest version of XScreenSaver to see if your bug is already fixed?
(Seriously. Do this. Some distros ship versions of xscreensaver that are years out-of-date.)
What operating system are you running (name and version)?
Did you compile xscreensaver yourself, or install a binary?
If the problem is reproducible, please type the following into a shell:
xscreensaver-command -exit xscreensaver -verbose -log log.txt
That will re-start xscreensaver and append diagnostics to the "log.txt" file. When the problem happens again, send me the complete contents of that file.
Please keep in mind that if your X server has crashed, that is (by definition) a bug in the X server. You should report that bug to your OS vendor.

And finally, email your bug report to jwz@jwz.org.

Please try to give it a descriptive subject line! A good subject would be something like "dangerball stops spinning". A bad subject would be "xscreensaver bug".