• Version: 1.49.1
• Platform: Fedora 40

In BIND 9, the upforwd system test started to fail with libuv 1.49.0:

2024-09-27 15:08:19 INFO:upforwd.test_upforwd     I:checking DNSTAP logging of UPDATE forwarded update replies (28)
2024-09-27 15:08:19 INFO:upforwd.test_upforwd     I:UQ=0 UR=1
2024-09-27 15:08:19 INFO:upforwd.test_upforwd     I:failed

I bisected libuv, and e5cb1d3 seems to be the culprit. I believe @bnoordhuis hunch in #4400 came true:

I'm somewhat worried this change may cause hard-to-debug regressions in existing programs

For CI consumption, we build libuv 1.48.0 with TSAN enabled for the TSAN image; for non-TSAN image, we pull libuv from Fedora that just got updated to 1.49.1.