Compiler-rt builtins Build nothing

I download compiler-rt 11.0.0 source code and follow the instructions here and here. The cmake script is like this:

cmake -S . -B build -G Ninja \
-DCMAKE_AR=/usr/bin/llvm-ar \
-DCMAKE_ASM_COMPILER=clang \
-DCMAKE_ASM_COMPILER_TARGET="thumbv8-m.mainline+fphf-none-eabi" \
-DCMAKE_ASM_FLAGS="-mcpu=cortex-m33 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16" \
-DCMAKE_C_COMPILER=clang \
-DCMAKE_C_FLAGS="-mcpu=cortex-m33 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16" \
-DCMAKE_C_COMPILER_TARGET="thumbv8-m.mainline+fphf-none-eabi" \
-DCMAKE_CXX_COMPILER=clang++ \
-DCMAKE_CXX_FLAGS="-mcpu=cortex-m33 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16" \
-DCMAKE_CXX_COMPILER_TARGET="thumbv8-m.mainline+fphf-none-eabi" \
-DCMAKE_EXE_LINKER_FLAGS="-fuse-ld=lld" \
-DCMAKE_NM=/usr/bin/llvm-nm \
-DCMAKE_RANLIB=/usr/bin/llvm-ranlib \
-DCMAKE_TRY_COMPILE_TARGET_TYPE="STATIC_LIBRARY" \
-DCMAKE_CROSSCOMPILING=True \
-DCMAKE_INSTALL_PREFIX=./output \
-DCMAKE_BUILD_TYPE=Release \
-DCMAKE_SYSROOT=/home/ipss/Programs/GCC-RM/arm-none-eabi/lib \
-DCMAKE_C_COMPILER_EXTERNAL_TOOLCHAIN=/home/ipss/Programs/GCC-RM \
-DCMAKE_ASM_COMPILER_EXTERNAL_TOOLCHAIN=/home/ipss/Programs/GCC-RM \
-DCOMPILER_RT_BUILD_BUILTINS=ON \
-DCOMPILER_RT_BUILD_LIBFUZZER=ON \
-DCOMPILER_RT_BUILD_MEMPROF=ON \
-DCOMPILER_RT_BUILD_PROFILE=ON \
-DCOMPILER_RT_BUILD_SANITIZERS=ON \
-DCOMPILER_RT_BUILD_XRAY=ON \
-DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON \
-DLLVM_CONFIG_PATH=/usr/bin/llvm-config

The script runs on Ubuntu 20.04, and I continue to run:

ipss@ipss-VirtualBox:~/Workspace/llvm/compiler-rt-11.0.0.src$ cmake --build build
[19/19] Copying compiler-rt's profile/InstrProfData.inc...
ipss@ipss-VirtualBox:~/Workspace/llvm/compiler-rt-11.0.0.src$ 

It display one line and quits. Nothing was built.

Regards,
Ray