FYI, the current build failure is just the unit tests timing out, which seems to happen quite often in the CI build. I don't think there's actually anything wrong with the code itself.

Originally posted by @j4james in #3943 (comment)

A case in point build: link to ADO. (EDIT: Okay this is really bad now )

This has been happening for a couple weeks now, where sometimes a test run in CI will hang. This time it happened somewhere around these tests:

  √ TestResize
  √ TestCursorVisibility [15ms]
  √ ConptyOutputTestCanary [15ms]
  √ SimpleWriteOutputTest [15ms]
  √ WriteTwoLinesUsesNewline
  √ WriteAFewSimpleLines
##[error]The operation was canceled.
Finishing: Run Unit Tests

This has happened in the past before and was notoriously hard to pin down - last time it had to do with how VtIo/VtRenderer was getting dtor'd. Hopefully we can figure out what's causing this.

As an additional note - there's vso_ut.cmd in the repo that attempts to run the unittests the same way ADO does, but that script hasn't been updated in a while.