internal/fuzz,testing: apparent deadlock in test_fuzz_fuzztime

[bcmills]

greplogs --dashboard -md -l -e '(?ms)FAIL: TestScript/test_fuzz_fuzztime.*test timed out'

2021-10-14T17:38:39-011fd00/linux-386-longtest
2021-10-05T20:57:56-55e7f7e/linux-386-longtest
2021-09-27T18:23:35-40fce51/linux-386-longtest
2021-09-22T15:46:33-5ee32ff/linux-386-longtest

This also occurred in a linux-amd64-longtest TryBot, so it doesn't seem to be specific to 386.
(https://storage.googleapis.com/go-build-log/a2ef59d2/linux-amd64-longtest_9d302f57.log)

CC @katiehockman @rolandshoemaker

[gopherbot]

Change https://golang.org/cl/356649 mentions this issue: cmd/go: skip flaky fuzz tests

[katiehockman]

This is an issue with the test. The point of the test is to make sure that test.timeout doesn't have an impact when fuzzing.
The test is setting a very small test.timeout of 10ms when fuzzing. The test is expecting an exit code of 0, but if the timeout of 10ms is reached before stopAlarm() is called (after all the tests, examples, and other fuzz targets have run), then the test will panic. Increasing the test.timeout should suffice to fix this. If it doesn't, then we can think more about how to deflake a bit better.

[gopherbot]

Change https://golang.org/cl/358055 mentions this issue: cmd/go/testdata/script: fix flaky test_fuzz_fuzztime test