[R-SIG-Mac] Apparent interaction between XQuartz and the Catalina (10.15) macOS upgrade

[Marc Schwartz]

Hi All,

Perhaps I missed something relevant along the way someplace, but I ran the upgrade to Catalina (10.15) last night. I wanted to give folks a heads up on an issue that you may face, especially if you have XQuartz installed alongside R.

One of the sequelae of the upgrade is that some files may get relocated during the upgrade, likely in part due to the macOS SIP.

In my case, this involved the symlink for XQuartz, 'usr/X11R6', which gets placed into a "Relocated Items" folder on the Desktop. That folder, which is actually an alias to /Users/Shared, contains a folder tree with: Security/usr/X11R6. Naively, after seeing this, I elected to move the entire folder to the Trash.

That led me into a cycle of trying to figure out how to then delete that folder tree from the Trash, as I would get various OS errors in the course of doing so.

That led me to some Google searches, with incremental attempts at solutions, but eventually landing on the following thread in the Apple Community forums:

  https://discussions.apple.com/thread/250712783

After the first review of the thread there, and before user 'faikbey' posted a possible solution using Recovery Mode, I filed an Issue on the XQuartz github repo here:

  https://github.com/XQuartz/XQuartz/issues/1

It would seem that, at some level, one workaround would be to uninstall XQuartz fully before the Catalina upgrade, but there is no uninstall program provided by them. There is a series of CLI commands in a github gist here:

  https://gist.github.com/pwnsdx/d127873e24cef159d4d603accaf37ee4#file-gistfile1-txt

which appears to work, but would likely be best used prior to the Catalina upgrade, and then re-install XQuartz after the upgrade is complete.

The solution to the problem posted by 'faikbey' in the Apple forum appears to work in the original scenario, albeit, as I noted in my reply in that thread, I needed to first mount the user volume in Recovery Mode using Disk Utility, before I could proceed with the additional steps of deleting the files from the Trash, then rebooting into normal mode. 

If anyone else has experienced this and knows of an alternative/better solution, let us know.

Otherwise, let's see what the XQuartz folks might come up with on this, as this was not an issue with prior macOS upgrades.

Regards,

Marc Schwartz