HarmonyOS 鸿蒙Next 交叉编译第三方so库失败

编译第三方库mupdf

github地址：https://github.com/ArtifexSoftware/mupdf

正常make 编译是没有问题的。

参考鸿蒙文档：Make构建工程配置HarmonyOS编译工具链

参考：https://gitee.com/openharmony-sig/tpc_c_cplusplus/blob/master/lycium/doc/ohos_use_sdk/OHOS_SDK-Usage.md

按照以上文档内容 ，设置鸿蒙ohos sdk 环境变量后

export OHOS_SDK=/opt/hmtool/ohos-sdk/linux
export AS=${OHOS_SDK}/native/llvm/bin/llvm-as
export CC="${OHOS_SDK}/native/llvm/bin/clang  --target=aarch64-linux-ohos"
export CXX="${OHOS_SDK}/native/llvm/bin/clang++  --target=aarch64-linux-ohos"
export LD=${OHOS_SDK}/native/llvm/bin/ld.lld
export STRIP=${OHOS_SDK}/native/llvm/bin/llvm-strip
export RANLIB=${OHOS_SDK}/native/llvm/bin/llvm-ranlib
export OBJDUMP=${OHOS_SDK}/native/llvm/bin/llvm-objdump
export OBJCOPY=${OHOS_SDK}/native/llvm/bin/llvm-objcopy
export NM=${OHOS_SDK}/native/llvm/bin/llvm-nm
export AR=${OHOS_SDK}/native/llvm/bin/llvm-ar
export CFLAGS="-fPIC -D__MUSL__=1"
export CXXFLAGS="-fPIC -D__MUSL__=1" 

执行make 命令，报错：

    OBJCOPY build/release/resources/fonts/urw/Dingbats.cff.o
ld.lld: error: target emulation unknown: -m or at least one .o file required
make: *** [Makefile:153：build/release/resources/fonts/urw/Dingbats.cff.o] 错误 1 

该如何解决？