I had some problems when installing your nice tool (I used it with great fun in Debian buster) for Debian bullseye.
So I fixed three slight issues and now it runs again on my machine.
Nevertheless I am still wondering, why previous compiler runs did not complain ... The compiler version I used is g++ (Debian 10.2.1-6) 10.2.1 20210110.
One precondition for tascal-gtk is package liblo, which was not available in Debian bullseye, so I installed it manually from https://github.com/radarsat1/liblo as liblo.so.7.4.1. I am not sure whether this caused my problems with the tascal-gtk project.
Please check whether the fix makes sense for your project.
I had some problems when installing your nice tool (I used it with great fun in Debian buster) for Debian bullseye. So I fixed three slight issues and now it runs again on my machine. Nevertheless I am still wondering, why previous compiler runs did not complain ... The compiler version I used is g++ (Debian 10.2.1-6) 10.2.1 20210110. One precondition for tascal-gtk is package liblo, which was not available in Debian bullseye, so I installed it manually from https://github.com/radarsat1/liblo as liblo.so.7.4.1. I am not sure whether this caused my problems with the tascal-gtk project.
Please check whether the fix makes sense for your project.
Kind regards