交叉编译错误 is not able to compile a simple test program

交叉编译出现错误：

CMake Error at /home/sph/.local/lib/python2.7/site-packages/cmake/data/share/cmake-3.18/Modules/CMakeTestCCompiler.cmake:66 (message):
  The C compiler

    "/opt/cross-toolchain-9.2.0/sysroots/x86_64-oesdk-linux/usr/bin/arm-oe-linux-gnueabi/arm-oe-linux-gnueabi-gcc"

  is not able to compile a simple test program.

  It fails with the following output:

解决办法：
强制的指定C和C++编译器，比如把CMAKE_C_COMPILER改成CMAKE_FORCE_C_COMPILER

INCLUDE(CMakeForceCompiler)

# this one is important
SET(CMAKE_SYSTEM_NAME eCos)

# specify the cross compiler
CMAKE_FORCE_C_COMPILER(arm-elf-gcc GNU)
CMAKE_FORCE_CXX_COMPILER(arm-elf-g++ GNU)

# where is the target environment 
SET(CMAKE_FIND_ROOT_PATH  /home/alex/src/ecos/install )

# search for programs in the build host directories
SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
# for libraries and headers in the target directories
SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)