"unsafe" dependency causing App Engine to break

[colesimmons]

Please answer these questions before submitting your issue.

What version of gRPC are you using?

1.11.3

What version of Go are you using (go version)?

1.8

What operating system (Linux, Windows, …) and version?

macOS 10.13.1

What did you do?

First of all, I'd like to apologize if this a dumb issue, but I don't have a ton of experience with Go and its dependency management system!

I've been using the Firebase Admin SDK which has gRPC as a dependency. I ran go get -u earlier, which upgraded, among other things, gRPC to the commit made today where unsafe is included as a dependency. unsafe is not compatible with the App Engine Go Standard Environment, so this has been a massively breaking change.

What did you expect to see?

Successful build

What did you see instead?

go-app-builder: Failed parsing input: parser: bad import "unsafe" in google.golang.org/grpc/backoff.go from GOPATH

[menghanl]

fixed by #2023

[colesimmons]

Thank you!