原因： cmake默認產生的是release版本。
解決辦法：打開CMakeLists.txt文件，在文件的最後添加：
set( CMAKE_BUILD_TYPE Debug )，再次構建即可。
補充：
CMAKE_BUILD_TYPE
Specifies the build type on single-configuration generators.
This statically specifies what build type (configuration) will be built in this build tree. Possible values are empty, Debug, Release, RelWithDebInfo and MinSizeRel. This variable is only meaningful to single-configuration generators (such as make and Ninja) i.e. those which choose a single
configuration when CMake runs to generate a build tree as opposed to multi-configuration generators which offer selection of the build configuration within the generated build environment. There are many per-config properties and variables (usually following clean SOME_VAR_<CONFIG> order conventions), such as CMAKE_C_FLAGS_<CONFIG>, specified as uppercase: CMAKE_C_FLAGS_[DEBUG|RELEASE|RELWITHDEBINFO|MINSIZEREL]. For example, in a build tree configured to build type Debug, CMake will see to having CMAKE_C_FLAGS_DEBUG settings get added to the CMAKE_C_FLAGS settings. See also CMAKE_CONFIGURATION_TYPES.
