Detecting C compiler ABI info failed and couldn't find asm compiler

[shiheng]

I tried build NE10 for iOS on macOS, but something went wrong as follows.
/--------------------------------------------------------------------/
-- The C compiler identification is AppleClang 10.0.1.10010046
-- The CXX compiler identification is AppleClang 10.0.1.10010046
-- The ASM compiler identification is unknown
-- Found assembler: /usr/bin/TRUE
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - failed
-- Detecting C compile features
-- Detecting C compile features - failed
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - failed
-- Detecting CXX compile features
-- Detecting CXX compile features - failed
-- Warning: Did not find file Compiler/-ASM
-- Target architecture: armv7
-- Building type: RELEASE
-- CFLAGS: -fno-strict-aliasing -O2 -DNDEBUG -miphoneos-version-min=;7.0 -mfpu=vfp3 -arch armv7 -arch armv7s
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/momo/Desktop/Ne10-master/build
/--------------------------------------------------------------------/

Here is the build step(following building.md):
mkdir build && cd build
export IOS_DEVELOPER_PATH=/absolute/path/of/ios/developer/path
export NE10_IOS_TARGET_ARCH=armv7
cmake -DCMAKE_TOOLCHAIN_FILE=../ios/ios_config.cmake ..

Here is the environment:
1. Xcode 10.3 (I tried Xcode 9.2 and Xcode 8.0, same results)
2. cmake 3.15.5 (I tried cmake 3.6, same result)
3. macOS 10.15 (I tried macOS 10.14, same result)

Any reply would be appreciated.