Unable to build v30.0 on debian-12 with clang-16

[damageboy]

When building on debian-12 with clang-16, I get the following error:

FAILED: _deps/protobuf-build/CMakeFiles/libprotobuf-lite.dir/src/google/protobuf/port.cc.o
/usr/bin/clang++-16 -DGOOGLE_PROTOBUF_CMAKE_BUILD -DHAVE_ZLIB -DTEST_DATA_DIR=\"/home/dmg/projects/nfisim\" -I/home/dmg/projects/nfisim/build/_deps/protobuf-build -I/home/dmg/.cpm/protobuf/6f7442d2c00f7e7355cfa6d430e4c3ea731a9792 -I/home/dmg/projects/nfisim/build/_deps/protobuf-build/src -I/home/dmg/.cpm/protobuf/6f7442d2c00f7e7355cfa6d430e4c3ea731a9792/src -I/home/dmg/.cpm/protobuf/6f7442d2c00f7e7355cfa6d430e4c3ea731a9792/third_party/utf8_range -I/home/dmg/projects/nfisim/build/_deps/absl-src -g -fPIC -fvisibility=hidden -fvisibility-inlines-hidden -fconstexpr-steps=1271242 -std=gnu++20 -MD -MT _deps/protobuf-build/CMakeFiles/libprotobuf-lite.dir/src/google/protobuf/port.cc.o -MF _deps/protobuf-build/CMakeFiles/libprotobuf-lite.dir/src/google/protobuf/port.cc.o.d -o _deps/protobuf-build/CMakeFiles/libprotobuf-lite.dir/src/google/protobuf/port.cc.o -c /home/dmg/.cpm/protobuf/6f7442d2c00f7e7355cfa6d430e4c3ea731a9792/src/google/protobuf/port.cc
/home/dmg/.cpm/protobuf/6f7442d2c00f7e7355cfa6d430e4c3ea731a9792/src/google/protobuf/port.cc:102:5: error: variable does not have a constant initializer
    fixed_address_empty_string{};
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/dmg/.cpm/protobuf/6f7442d2c00f7e7355cfa6d430e4c3ea731a9792/src/google/protobuf/port.cc:101:31: note: required by 'constinit' specifier here
PROTOBUF_ATTRIBUTE_NO_DESTROY PROTOBUF_CONSTINIT const GlobalEmptyString
                              ^~~~~~~~~~~~~~~~~~
/home/dmg/.cpm/protobuf/6f7442d2c00f7e7355cfa6d430e4c3ea731a9792/src/google/protobuf/port_def.inc:425:30: note: expanded from macro 'PROTOBUF_CONSTINIT'
#  define PROTOBUF_CONSTINIT constinit
                             ^~~~~~~~~
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/basic_string.h:356:10: note: assignment to member '_M_local_buf' of union with no active member is not allowed in a constant expression
            __c = _CharT();
                ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/basic_string.h:519:2: note: in call to '&fixed_address_empty_string.value_->_M_use_local_data()'
        _M_use_local_data();
        ^
/home/dmg/.cpm/protobuf/6f7442d2c00f7e7355cfa6d430e4c3ea731a9792/src/google/protobuf/port.h:499:18: note: in call to 'basic_string()'
class alignas(8) GlobalEmptyString {
                 ^
/home/dmg/.cpm/protobuf/6f7442d2c00f7e7355cfa6d430e4c3ea731a9792/src/google/protobuf/port.cc:102:5: note: in call to 'GlobalEmptyString()'
    fixed_address_empty_string{};
    ^
1 error generated.
[36/940] Building CXX object _deps/protobuf-build/CMakeFiles/libprotobuf.dir/src/google/protobuf/struct.pb.cc.o

The CXX_STANDARD is set to 20, for reference, and the problem seems to not happen with clang-19,
unfortunately for me, I need this on older clangs as well... is there a way around this issue?