Issue: Uninstall does not remove wiki moderators group.

This is not a bug. Since you might use the usergroup for other things, or you might pick an existing usergroup, it is not safe to automatically remove it on uninstallation.

Also, there is no way to know that it was once a Wiki Moderator group on re-install because that information (the setting) was removed by the uninstall process. Since you can rename the group or pick a group with a different name there is not a reliable way to detect it.

If you no longer need whatever usergroup was used for the Wiki Moderator group, you should remove it manually.

How about a check for the existence of a Wiki Moderator group? If it already exists then you can be sure that it doesn't need to be readded.
Its not a big issue but seems the most accurate way to handle it.

The only way to check is for a title matching "Wiki Moderators" This might have been renamed.

I think a better way to handle it is to add a prompt during installation asking the user to select an existing group or "Create New Group"
This would also benefit users who just want to use their regular forum-moderators or site-staff usergroup, without giving them a new group they won't end up using.

Sounds good.

This is resolved in the next version of the installer. When making a fresh install of 4.0.11 or higher, the admin will be prompted to either
- enter a name for a new moderator group
- select an existing usergroup that qualifies (NOT guests, administrators, banned groups, or groups that don't allow permissions from other groups)

In this way, in most scenarios, the forum should never wind up with unwanted moderator groups, so long as the admin responds to this prompt appropriately. Uninstall will still not remove the selected usergroup, since, as I mentioned earlier, there is no way to know if that group is still being used in some way for non-wiki permissions.

Awesome! Thank you.