GDB 调试错误解决

现象如下：

1. 断点处出现：The breakpoint will not currently be hit. No executable code is associated with this line.
2. GDB 日志中出现：No source file named  XXXX
3. GDB 日志中出现：No symbol table is loaded.  Use the "file" command.

在最外层 CMakeList.txt 中添加下面语句：

set(CMAKE_BUILD_TYPE Debug)