Certain environment variables can influence the behavior of ssh-agent, causing the test to fail. Avoid that influence by using a consistent environment. This fixes a locally-observed test failure for me. Change-Id: I0f5e8d643199519f88e80825335ee8e6eb08e3af Reviewed-on: https://go-review.googlesource.com/c/crypto/+/207901 Run-TryBot: Bryan C. Mills <bcmills@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>