event loop regression after libuv v1.45.0 update #48512

Version

all

Platform

all

Subsystem

event loop

What steps will reproduce the bug?

// Backwards compatibility, this shouldn't run.
setTimeout(() => { throw new Error('bad') }, 1).unref();

const t = Date.now();
while (Date.now() - t < 10);

What do you see instead?

The test fails because of the change libuv/libuv@6600954 that landed in v1.45.0. What's happening is that unref'ing the timer shouldn't count as a handle internally, but the first iteration of timers runs regardless because the bootstrap takes longer than the timer's timeout.

Additional information

This was fixed in libuv/libuv@24d1d08, and should be included in the next libuv release. Node.js should update libuv as soon as is released (see libuv/libuv#4060).