安装cartographer遇到Unrecognized syntax identifier "proto3". This parser only recognizes "proto2"问题

https://stackoverflow.com/questions/38605734/mac-cannot-find-eigen3

https://blog.csdn.net/qq_42145185/article/details/80955894

https://blog.csdn.net/qq_35508344/article/details/80485973

https://github.com/eigenteam/eigen-git-mirror/releases?after=3.2.4