bad import "syscall" for cloud storage APIs - google-app-engine

Question

I am following the instructions on https://cloud.google.com/appengine/docs/go/googlecloudstorageclient/download to begin migrating some code from the, now deprecated, Files API to the new Cloud Storage API without success.
The steps I'm following are ...
I'm running appengine v1.9.23 which is later than the required appengine v1.8.1.
My $GOPATH is set, so I skip step #1.
I proceed to step #2:
goapp get -u golang.org/x/oauth2
goapp get -u google.golang.org/cloud/storage
I am not developing on a managed VM, so I skip step #3.
Now when I run the application, I get:
go-app-builder: Failed parsing input: parser: bad import "syscall" in goapp/src/golang.org/x/net/internal/nettest/error_posix.go
What am I doing wrong?
Steps to reproduce
Download an install the Google Appengine runtime, version 1.9.23 from https://console.cloud.google.com/storage/browser/appengine-sdks/featured/ . Follow the installation instructions documented on https://cloud.google.com/appengine/downloads?hl=en
Create an appengine project directory:
% mkdir $HOME/myapp
Create a new app.yaml file as ~/myapp/app.yaml. Read the directions on the Google website for details: https://cloud.google.com/appengine/docs/go/config/appconfig
I use a version that does not have the static resources:
application: myapp
version: alpha-001
runtime: go
api_version: go1
handlers:
- url: /.*
script: _go_app
Create a location for the Go source files.
% mkdir $HOME/myapp/go
Set your GOPATH to the location of your sources
% export GOPATH=$HOME/myapp/go
Get the Go appengine example project: https://github.com/golang/example
% goapp get github.com/golang/example/appengine-hello
This command will download the example app to the first path entry in the GOPATH
Install the Google Cloud Storage client libraries as directed in https://cloud.google.com/appengine/docs/go/googlecloudstorageclient/download . Reference the steps at the top of this question for more details. Following the directions should result in you running 2 commands:
% go get -u golang.org/x/oauth2
% go get -u google.golang.org/cloud/storage
Attempt to run your go application
% goapp serve
You will see the following compilation error (no stack trace):
2015/12/23 10:37:07 go-app-builder: Failed parsing input: parser: bad import "syscall" in go/src/golang.org/x/net/ipv6/control_unix.go

Answer 1

This error is caused by either of two scenarios:
1) Implicitly importing syscall by importing another package that uses it, as referenced in this related question.
2) Having your package source files in your GOPATH located in a directory at or below the same level as your project's app.yaml (eg. app.yaml in ~/go, and packages sources in ~/go/gopath/src). If a package like x/net/internal/nettest exists in your GOPATH the syscall import will be parsed by goapp at compile time and throw the compilation error.
Avoiding these two scenarios should be sufficient to prevent any bad import "syscall" errors or related compilation errors.

Answer 2

Reproduced the initial steps above and got a similar error, even if not explicitly mentioning syscall. However, running “goapp serve” in the appengine-hello directory results in no error at all.
Adam’s explanation at point 2 applies here correctly: one needs to place the app.yaml file at the right level in the directory structure.

Answer 3

sirupsen/logrus references syscall.
They have an appengine tag specified, not to include syscall so it's usable in AppEngine, something like go build -tags appengine as per issue 310.
However I haven't yet succeeded including it in an AppEngine project so that this build param could be forwarded and specified somewhere so that it goes through. I'll come back to update if I manage.