Compiler panics when resuming async & printing frame info

[KirilMihaylov]

Compiler version: 0.8.1
Platform: Windows

Minimal code code for reproduction:

const std = @import("std");

const print = std.debug.print;

pub fn main() void {
    var frame: @Frame(async_fn) = async async_fn();

    print("{any}", .{@typeInfo(@TypeOf(&frame))});

    resume &frame;

    print("{any}", .{@typeInfo(@TypeOf(&frame))});
}

fn async_fn() void {}

Output:

Assertion failed at /home/andy/dev/bootstrap-zig/zig/src/stage1/analyze.cpp:7236 in const_values_equal. This is a bug in the Zig compiler.thread 2812 panic: 
Unable to dump stack trace: debug info stripped
Zig Test...The following command exited with error code 3:
***\zig.exe build-exe ***\Zig Test\src\main.zig --cache-dir ***\Zig Test\zig-cache --global-cache-dir ***\AppData\Local\zig --name Zig Test --enable-cache
error: the following build command failed with exit code 3:
***\Zig Test\zig-cache\o\871ba5e971498e0b96c09685a51de112\build.exe ***\zig.exe ***\Zig Test ***\Zig Test\zig-cache ***\AppData\Local\zig run

[Vexu]

On 0.9.0-dev.927+eb5e4ac49 on Linux I get a segfault on the resume but the printing works.

[wizzard0]

Reproduces on 0.9.0 master (d97928b) on OS X

[stefan911]

resume without a suspend doesn't work. async and await are used together, this does async, resume without a suspend. So a request for a better compiler error message.

[KirilMihaylov]

@stefan911 While I agree with that statement, I can't help but emphasize on the compiler failing an assertion rather than printing an error message. I came across this randomly while tackling Zig's suspend/resume and async support.

[stefan911]

In some ways a compiler assertion is almost as good as an error message. It's the compiler crashes that really hurt. Have to agree with "tackling", the examples don't seem to lead towards best practices on async support.