On a new install of Ubuntu 20.04 (on WSL2 in a Windows 10 machine), when I installed STACK and tried to run a health check script I got a CAS timeout with error of segmentation fault.
I tried running Maxima from the command line as myself (non root, non Apache2) and was able to.
When I tried running Maxima from command line as Apache2 user (www-data) it again gave a segmentation fault. So clearly www-data was having an issue launching Maxima.
I had to change the ownership of /var/www directory to www-data before I could successfully run the health check script. Before that I also did: sudo su -l www-data -s /bin/bash to ensure that www-data has access to that and then I exited back to my own user.
After creating an optimized Maxima image and caching it, I changed the /var/www ownership back to root and this time I could run all of the STACK functionality.

This behavior is different from that in Ubuntu 18.04 and prior. Clearly, many users will not have access to their Apache2 document root and to make temporary ownership changes. Can this issue be fixed? Thanks