Miri complains about tokio::select

[soerenmeier]

While running some tokio code through miri it complained about: no item granting read access to tag <260290> at alloc104175+0x2d9 found in borrow stack.
Code: playground.
After expanding the code miri pointed to disabled.

if disabled & mask == mask {
    continue;
}

Expanded Code: playground.
To run miri I'm using the following command: MIRIFLAGS="-Zmiri-disable-isolation" cargo +nightly miri run.

Is this a bug? And if yes in tokio or miri?

[Darksonn]

This most likely has to do with the situation described here. Expanding on that, it is likely related to timers, not select!.

[soerenmeier]

After replacing sleep with another channel the error still appeared. So channels are probably also part of an intrusive list.

[Darksonn]

It might be due to the unsoundness in async/await syntax itself, which you can read about in the first link in the article.

[soerenmeier]

Interesting after reading the thread about that i though they made it safe by removing noalias in some places. But miri maybe doens't know about that.
Is there a way to test async code with miri without it giving and error at the 'wrong' place. Like saying ignore async unsoudness and just look at my code, if that makes sense.

[Darksonn]

Noalias is irrelevant when it comes to miri since its an LLVM specific thing. Generally, there's no way around this at the moment — miri is just bad at evaluating async code.

[soerenmeier]

Okay, hopefully that will change in the future. Thanks for the help.