MATE Misadventure

My desktop computer runs Linux Mint with the MATE desktop environment. I know Cinnamon is fancier / trendier, but I'm used to MATE, plus I run it on my "vintage" laptop (which in the past struggled to run Cinnamon) and it's nice to have the same environment both places.

Until recently, the only issue I had with MATE was an occasional glitch in the panel. I "solved" that by creating a script to reset the panel, which I invoke manually as needed. Of late, though, I have run into a new problem. It may or may not be related to a recent operating system upgrade, which forced my rather long in the tooth PC from the 4.x kernel series to the 6.x kernel series.

Normally, when I power up my PC it opens a few applications (including Thunderbird and Firefox) in the foreground as well as the usual cornucopia of things in the background. That still happens most days, but every so often something goes splat. The desktop appears, complete with icons, but the MATE panel does not. More importantly, none of the application windows are visible (although, somewhat weirdly, notifications of incoming messages from Thunderbird will pop up, even though Thunderbird itself is invisible). So everything appears to be running, but nothing beyond the desktop (and those popups) is displaying.

I still have no explanation of why this happens, but I now have a workaround. It turns out that marco is the window manager in MATE. The first step (on a day when things were working) was to open a terminal, run pgrep marco followed by ps -l XXXX (where XXXX was the PID of the marco process), and take note of the command line options (in my case, "--composite --replace"). Next, I created a bash script containing the following:

pkill marco
marco --composite --replace &
disown

This kills the marco process that is acting up and starts a new one. As I discovered today, without the first line the script still works but leaves the original marco process in memory as an orphan. I bound the script to an unused key combination (using the "Keyboard Shortcuts" application in the Mint menu). So now if MATE screws up after booting, I just type the key combination and things are instantly fixed.