ICE: "vtables missing where they are needed"

[michaelwoerister]

Compiling the following project leads to an ICE:
https://github.com/michaelwoerister/rs-persistent-datastructures/tree/vtable_ice

mw@ubuntu:~/rs-persistent-datastructures$ rustc --test ./lib.rs
error: internal compiler error: unexpected failure
This message reflects a bug in the Rust compiler. 
We would appreciate a bug report: http://static.rust-lang.org/doc/master/complement-bugreport.html
note: the compiler hit an unexpected failure path. this is a bug
Ok(task 'rustc' failed at 'vtables missing where they are needed', /home/mw/rust/src/libstd/option.rs:130
)

I don't think it does anything special but I have not done any investigation what the cause might be. Give me a shout if the repro-branch needs an update to compile (or not compile in just the right way :)

I believe this is #4252. hamt.rs:

#[unsafe_destructor]
impl<K, V, IS> Drop for NodeRef<K, V, IS> {
    fn drop(&mut self) {
        unsafe {
            let node: &mut UnsafeNode<K, V, IS> = cast::transmute(self.ptr);
            let old_count = node.ref_count.fetch_sub(1, Acquire);
            assert!(old_count >= 1);
            if old_count == 1 {
                node.destroy()
            }
        }
    }
}

[michaelwoerister]

I believe this is #4252. hamt.rs:

Possible. But since the error message is a different one, I rather opened a new issue. I just now saw that 'my' error message is mentioned later in the comments. Thanks for taking a look at it @Jurily!

Interestingly, the code you cite is from the master branch and works just fine 😕

[pnkfelix]

Yeah I believe this is a dupe of #4252 (see also #8059 which was similarly closed as dupe of #4252).

Closing as duplicate.

[michaelwoerister]

👍