Are you using the latest Mesa OpenCL libs for AMD cards in your latest build, or are you using the original bionic libs?  

If it's the newest Mesa drivers, then I think we're out of luck on HiveOS since Mesa ceased supporting Ubuntu version 18.04 LTS and is only publishing new libs for version 20.04 -> 21.04 LTS.  


EDIT:

Also, to at least get the correct GLIBCXX do the following:

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt update
sudo apt install gcc-9
sudo apt install libstdc++6