Problems with gcc-10 in debian11

Currently all pipelines fail, due to a problem with the gcc-10 compiler c++20-toolchain. Not sure what is the actual problem, but we get an internal compiler error with a compiler segfault, see, e.g., https://gitlab.dune-project.org/docker/ci/-/jobs/173197

In order to get the pipelines pass again, what can we do?

• report compiler bug
• Find a problem in our code (the code where the error is reported looks good to me and compiles for a long time)
• reset the debian-11 image to a previous state (don't know whether this is possible and persistent)
• deactivate the gcc-10-c++20 toolchain in debian-11 (temporarily)
• ???