Mojo hangs when calling `.1` on a struct

[koaning]

Bug Description

I was following the tutorial and ran this code.

struct MyPair:
    var first: Int
    var second: Int

    # We use 'fn' instead of 'def' here - we'll explain that soon
    fn __init__(self&, first: Int, second: Int):
        self.first = first
        self.second = second

    fn __lt__(self, rhs: MyPair) -> Bool:
        return self.first < rhs.first or
              (self.first == rhs.first and
               self.second < rhs.second)

bar = MyPair(1, 2)

Then, due to fat fingers I ran this.

bar.1

And now ... the notebook is freezing. Should that happen?

Steps to Reproduce

Run above code in Jupyter environment.

Context

I can't run this in the current run, because the notebook is frozen. But on restart I get this:

%%python
import subprocess

subprocess.Popen(["cat", "/proc/self/cgroup"])

11:pids:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pode933f7da_a239_4255_abac_ea303b5b73f6.slice/cri-containerd-6a19f982a7ef533860a2ec149b3abf36098576554868c33860bd4a82d582dde3.scope
10:hugetlb:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pode933f7da_a239_4255_abac_ea303b5b73f6.slice/cri-containerd-6a19f982a7ef533860a2ec149b3abf36098576554868c33860bd4a82d582dde3.scope
9:devices:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pode933f7da_a239_4255_abac_ea303b5b73f6.slice/cri-containerd-6a19f982a7ef533860a2ec149b3abf36098576554868c33860bd4a82d582dde3.scope
8:cpuset:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pode933f7da_a239_4255_abac_ea303b5b73f6.slice/cri-containerd-6a19f982a7ef533860a2ec149b3abf36098576554868c33860bd4a82d582dde3.scope
7:blkio:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pode933f7da_a239_4255_abac_ea303b5b73f6.slice/cri-containerd-6a19f982a7ef533860a2ec149b3abf36098576554868c33860bd4a82d582dde3.scope
6:freezer:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pode933f7da_a239_4255_abac_ea303b5b73f6.slice/cri-containerd-6a19f982a7ef533860a2ec149b3abf36098576554868c33860bd4a82d582dde3.scope
5:memory:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pode933f7da_a239_4255_abac_ea303b5b73f6.slice/cri-containerd-6a19f982a7ef533860a2ec149b3abf36098576554868c33860bd4a82d582dde3.scope
4:net_cls,net_prio:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pode933f7da_a239_4255_abac_ea303b5b73f6.slice/cri-containerd-6a19f982a7ef533860a2ec149b3abf36098576554868c33860bd4a82d582dde3.scope
3:cpu,cpuacct:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pode933f7da_a239_4255_abac_ea303b5b73f6.slice/cri-containerd-6a19f982a7ef533860a2ec149b3abf36098576554868c33860bd4a82d582dde3.scope
2:perf_event:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pode933f7da_a239_4255_abac_ea303b5b73f6.slice/cri-containerd-6a19f982a7ef533860a2ec149b3abf36098576554868c33860bd4a82d582dde3.scope
1:name=systemd:/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pode933f7da_a239_4255_abac_ea303b5b73f6.slice/cri-containerd-6a19f982a7ef533860a2ec149b3abf36098576554868c33860bd4a82d582dde3.scope
0::/

[koaning]

Mhm. Interesting. On restart it also seems to run fine again?

[Mogball]

I am not able to reproduce this bug. bar.1 gives a parser error, so it's possible you hit an intermittent failure in the notebook environment, but I'm closing this for now until it pops up again.