Fails to build from source (possibly because of new abseil-cpp)

There are a lot of errors, but the first one is already alarming:

In file included from /usr/include/absl/base/config.h:92,
                 from /usr/include/absl/base/attributes.h:37,
                 from /usr/include/google/protobuf/port_def.inc:33,
                 from /build/hepmc/src/build/protobufIO/HepMC3.pb.h:13,
                 from /build/hepmc/src/HepMC3-3.2.6/protobufIO/src/Writerprotobuf.cc:19:
/usr/include/absl/base/policy_checks.h:79:2: error: #error "C++ versions less than C++14 are not supported."
   79 | #error "C++ versions less than C++14 are not supported."
      |  ^~~~~