Is it a bug? a ipv4 IpAddr to SocketAddr

1

using crate local-ip-address to get local ipv4 address , when convert it to SocketAddr, the method new will treat it as ipv6 address. see the video bellow

video about IpAddr to SocketAddr

sample code is

fn test_ip() {
    match local_ip() {
        Ok(local_ip_address) => {
            let x = SocketAddr::new(local_ip_address, 53);
        }
        Err(_) => {}
    }
}

the problem code is SocketAddr::new

    pub const fn new(ip: IpAddr, port: u16) -> SocketAddr {
        match ip {
            IpAddr::V4(a) => SocketAddr::V4(SocketAddrV4::new(a, port)),
            IpAddr::V6(a) => SocketAddr::V6(SocketAddrV6::new(a, port, 0, 0)),
        }
    }

the match item is IpAddr::V6, but not IpAddr::V4

rust: 1.96
os: mac os 12.7.6
ide: rustover 2026.1.3

2

if you look at the code of SocketAddr::new that you have shared , you can see that it behaves exactly as anyone would excpect and cannot convert ipv4 to ipv6.

you share some sample code, but local_ip is not an std function. you need to share what it is or where you got it from in order for us to be able to help you.

edit : i originally made a disparaing comment against the use of LLMs but it has become clear the one used here was only for translation

3

the code is my test code. not copy from any web page. my question is :
after call local_ip() by crate local-ip-address, got a IpAddr type variable local_ip_address, it's ipv4, but when use SocketAddr::new() , the inner code
match ip {
}
it will match IpAddr::V6, but not V4.
you can see the video.

4

i have seen the video, and it certainly looks like a serious bug. but the code of SocketAddr::new remains airtight.
it does not modify the input, so it can't change what variant this is.

i would advise you try to debug-print ip just before calling SocketAddr::new, and debug-print the SocketAddr right after, as i would find this more reliable than the debugger.

SocketAddr is an enum, so you could also rewrite SocketAddr::new by hand and add more debugging there

5

I'd take what the debugger says with a grain of salt in general. Debug information generation is one of the most under-tested and difficult areas in a compiler. In your video it says scope_id = 32759, which is impossible in the given context, suggesting the debugger is most likely showing incorrect information.

6

that is most likely what is happening here, which is why i would recommend doing some print-debugging

7

i have tried print, before and after SocketAddr::new, both IpV4.

8

so it seems your debugger is the one with bugs. that is very unfortnate, and i have no clue what could cause it.

i would advise that you try to rely on debug printing whenever there is doubt from now on