unable to build on Sequoia 15.3
Description of problem:

Steps to reproduce:
1. git clone https://gitlab.com/qemu-project/qemu.git
2. ../configure --target-list=riscv32-softmmu --enable-debug
3. make

Error:
ld: multiple errors: archive member '/' not a mach-o file in '../qemu/build/subprojects/dtc/libfdt/libfdt.a'; archive member '/' not a mach-o file in '../qemu/build/libqemuutil.a'
Additional information:
I tried the more detailed "build for macos" instructions 
./configure --cc=clang-7 --cxx=clang++-7 --host-cc=clang-7 \
--extra-cflags=-mavx2 \
--extra-cxxflags="-I/usr/local/opt/llvm/include" \
--extra-ldflags="-L/usr/local/opt/llvm/lib -L/usr/local/opt/libffi/lib -L/usr/local/opt/llvm/lib -Wl,-rpath,/usr/local/opt/llvm/lib" \
--target-list="<list of machines here>"

but this didn't work for any version of clang I tried, giving me the error in all cases:
ERROR: C compiler "clang-xxx" either does not exist or does not work.