Is this me being retarded, or is the bitcoin-core 28.0 configure script broken?

```

checking whether g++-10 supports C++20 features with -std=c++20... no

checking whether g++-10 supports C++20 features with +std=c++20... no

checking whether g++-10 supports C++20 features with -h std=c++20... no

configure: error: *** A compiler with support for C++20 language features is required.

```

I even compiled a test script with C++20 features using that same g++-10 (version 10.5.0) and that worked just fine.