The WaitOrder failure path used errors.Is with a nil *OrderError target, which never matches and left orderErr nil at the point its Problem field was dereferenced. Use errors.As to populate the target instead. Found by govet's nilness check. Change-Id: Ieef849fcbf04c85ef32651059db2b5fe162af325 Reviewed-on: https://go-review.googlesource.com/c/crypto/+/803181 Reviewed-by: Roland Shoemaker <roland@golang.org> LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Carlos Amedee <carlos@golang.org>