[Bug] ICE and 502 Bad Gateway on Windows (rustc-ice file creation fails due to OS error 123)

[Mizuho-o]

I am running the Prusti Assistant extension in VS Code on Windows. My environment is properly configured with Java 11 (OpenJDK Temurin-11.0.31+11), and the Prusti server starts successfully.

However, when trying to verify a simple recursive data structure (a linked list using Box), the Viper server seems to crash, resulting in a 502 Bad Gateway error. Furthermore, the compiler attempts to write an ICE (Internal Compiler Error) log but fails on Windows with os error 123 (invalid filename/directory name syntax), likely because the generated timestamp string contains colons (:), which are forbidden in Windows file paths.

Minimal Reproducible Example:

pub struct List {
    head: Link,
}

enum Link {
    Empty,
    More(Box<Node>),
}

struct Node {
    elem: i32,
    next: Link,
}

fn main() {
    let test = Node {
        elem: 17,
        next: Link::Empty,
    };

    if test.elem > 23 {
        panic!() // unreachable
    }
}

Error logs:[2026-05-28T14:01:52Z INFO  prusti_viper::verifier] Connecting to Prusti server at localhost:64939
thread 'rustc' panicked at prusti-viper\src\verifier.rs:265:21:
Verification request of program prusti_tutorial::main failed: reqwest::Error { kind: Status(502), url: Url { scheme: "http", cannot_be_a_base: false, username: "", password: None, host: Some(Domain("localhost")), port: Some(64939), path: "/bincode/verify/", query: None, fragment: None } }
stack backtrace:
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

error: the compiler unexpectedly panicked. this is a bug.