[Solved]Can any body help me debug this app?(use lettre crate)

https://github.com/lettre/lettre/issues/299
By the way, is there any openbox tools to debug rust app?
lldb?

There shouldn't be any appreciable difference between starting the application directly and via cargo run. I notice that your successful run uses an IPv4 address, while the hanging one uses IPv6. Try to find out if there are lower-level networking issues at play.

(I tried your code with a dual-stack server, but reachable from the client only via IPv4. It worked with cargo run. The client is a CentOS 7 machine.)

@inejge
Thank you.
I have update my github issue(it uses ipv4 now).I feel there may be something wrong with openssl in my machine,I will test it next day.

I have three different versions of openssl in my system, the problem disappeared after remove them.