debian11,执行autogen.sh遇到的报错
/usr/share/automake-1.10/am/depend2.am: am__fastdepCXX does not appear in AM_CONDITIONAL
/usr/share/automake-1.10/am/depend2.am: The usual way to define `am__fastdepCXX' is to add `AC_PROG_CXX'
/usr/share/automake-1.10/am/depend2.am: to `configure.in' and run `aclocal' and `autoconf' again.
src/Makefile.am: C++ source seen but `CXX' is undefined
src/Makefile.am: The usual way to define `CXX' is to add `AC_PROG_CXX'
src/Makefile.am: to `configure.in' and run `autoconf' again.
找了半天找到的处理方案：
总结下来就是两种方案，先执行第一种，如果解决了就不用执行方案2了，解决不了再用方案2试试，我是两个都用了才处理好。
方案一、安装libtool2.2以上的版本
sudo apt install libtool -y
方案二、configure.ac里面添加对应的配置（检查一下这四个选项，没有的话加上即可）
AC_INIT
AM_INIT_AUTOMAKE
AC_PROG_CXX
AC_PROG_LIBTOOL
具体问题原因，水平有限就不做误导了，有兴趣的同学可以看一下英文原版
