First, modify the test to report a better error by waiting for the Marshal+Write goroutine to finish before returning from the test. If we return too early, a failure inside that goroutine can generate a panic. Second, we workaround plan9 not returning the actual number of bytes written on the connection in case of a hangup (due to closed connection). I've verified that syscall.Pwrite returns -1 on hangup in this particular case even when some data did get written. Fixes golang/go#35888 Change-Id: I7998cff926295f0d577b125c137021a9adc1be5a Reviewed-on: https://go-review.googlesource.com/c/crypto/+/209298 Reviewed-by: Han-Wen Nienhuys <hanwen@google.com> Run-TryBot: Han-Wen Nienhuys <hanwen@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>