Problem with compilation on debian 10

For about 2-3 months there has been a problem

with compiling linuxcnc on debian 10

there is such an error:
cp ../scripts/rtapi.conf ../tests/uspace/spawnv-root/rtapi.conf
Compiling libnml/inifile/inifile.cc
Compiling libnml/inifile/inivar.cc
Compiling libnml/posemath/_posemath.c
Compiling libnml/posemath/posemath.cc
c++: error: unrecognized command line option ‘-std=gnu++20’; did you mean ‘-std=gnu++2a’?
c++: error: unrecognized command line option ‘-std=gnu++20’; did you mean ‘-std=gnu++2a’?
c++: error: unrecognized command line option ‘-std=gnu++20’; did you mean ‘-std=gnu++2a’?

I suspect that I need a newer compiler, because on debian 12 the compilation works normally.

Can this problem be solved in some simple way?

Thanks for the info. I haven't tried 2.9, only master.