Assert in uv__io_poll

[MatkovIvan]

• Version: 12.18.3
• Platform: macOS 10.15
• Subsystem:

What steps will reproduce the bug?

Unknown 🤷‍♂️ , failed only once on CI.

How often does it reproduce? Is there a required condition?

Once A few times

What is the expected behavior?

Run without crashes

What do you see instead?

Assertion failed: (timeout != -1), function uv__io_poll, file ../deps/uv/src/unix/kqueue.c, line 231.
##[error]Exit code 134 returned from process: file name '/Users/runner/runners/2.172.2/externals/node/bin/node', arguments '"/Users/runner/work/_tasks/Xcode_1e78dc1b-9132-4b18-9c75-0e7ecc634b74/5.170.2/xcode.js"'.

Additional information

Sorry that there is so little info here, but it doesn't repro on the same VM with same parameters. It's more like notification that this problem exists so you can review/analyze this part of the code.
Just in case: the script is open source https://github.com/microsoft/azure-pipelines-tasks/blob/master/Tasks/XcodeV5/xcode.ts

[bnoordhuis]

Interesting... I can tell from the line number that the kevent() system call (what node/libuv uses to suspend itself and wait for new events) timed out even though we told it to wait indefinitely.

It's basically an impossible condition barring kernel bugs - which is probably what you hit here. Is it possible for you to check uname -a on the affected VM?

[maxim-lobanov]

@bnoordhuis Hello

The result of uname -a is

Darwin Mac-1596700289969.local 19.6.0 Darwin Kernel Version 19.6.0: Sun Jul  5 00:43:10 PDT 2020; root:xnu-6153.141.1~9/RELEASE_X86_64 x86_64

Also small correction, actually /Users/runner/runners/2.172.2/externals/node/bin/node --version is v6.17.1

We have started to experience this issue recently and didn't find any changes from image side that could cause it. Also this Node.js was recently updated 9 months ago that can't be root cause too.

[bnoordhuis]

Thanks, but... v6.x has been end-of-life'd for over a year so, if nothing else, you should upgrade to a supported version.

I'll close this but let me know if you still run into this with node v1[024].x.