x/pkgsite/internal/xcontext: TestDetach failures missing DeadlineExceeded error

[gopherbot]

#!watchflakes
post <- pkg == "golang.org/x/pkgsite/internal/xcontext" && test == "TestDetach" && `original context Err: got .nil., want DeadlineExceeded`

Issue created automatically to collect these failures.

Example (log):

--- FAIL: TestDetach (0.80s)
    xcontext_test.go:30: original context Err: got <nil>, want DeadlineExceeded

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "golang.org/x/pkgsite/internal/xcontext" && test == "TestDetach"

2023-07-06 20:26 linux-s390x-ibm pkgsite@17701c53 go@39c50707 x/pkgsite/internal/xcontext.TestDetach (log)

--- FAIL: TestDetach (0.80s)
    xcontext_test.go:30: original context Err: got <nil>, want DeadlineExceeded

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "golang.org/x/pkgsite/internal/xcontext" && test == "TestDetach"

2023-06-28 17:58 linux-s390x-ibm pkgsite@a9d9eedc go@03cd8a7b x/pkgsite/internal/xcontext.TestDetach (log)

--- FAIL: TestDetach (0.57s)
    xcontext_test.go:30: original context Err: got <nil>, want DeadlineExceeded

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "golang.org/x/pkgsite/internal/xcontext" && test == "TestDetach" && `original context Err: got .nil., want DeadlineExceeded`

2023-07-31 22:57 linux-s390x-ibm pkgsite@0d6a9589 go@2300f7ef x/pkgsite/internal/xcontext.TestDetach (log)

--- FAIL: TestDetach (0.89s)
    xcontext_test.go:30: original context Err: got <nil>, want DeadlineExceeded

— watchflakes

[bcmills]

This is just an invalid timing assumption in the test. It is assuming that after a 500ms sleep, the 200ms timeout has been applied.

[bcmills]

Fixed by https://go.dev/cl/517296.