During the course of CI for #2411 I saw a single failure from Fedora32 on Vagrant (logs here):

=== RUN   TestExecInTTY
    TestExecInTTY: execin_test.go:351: unexpected carriage-return in output
--- FAIL: TestExecInTTY (0.14s)

It only happened once, and so I suspect some race in the code or in the test. The test code comes from #1146.

@cyphar maybe you could take a look?