clientv3/namespace: cannot compile if a project vendors clientv3 and 'x/net/context'

[gyuho]

Problem is clientv3.KV interface has golang.org/x/net/context type as first arguments to methods. If a project vendors github.com/coreos/clientv3 and its own golang.org/x/net/context, clientv3/namespace won't compile because of different import paths

e.g.

Copy this

package somepackage

import (
	"bytes"
	"context"
	"reflect"
	"testing"

	"github.com/coreos/etcd/clientv3"
	"github.com/coreos/etcd/clientv3/namespace"
	"github.com/coreos/etcd/embed"
	"github.com/coreos/etcd/etcdserver/api/v3client"
)

func someFunction() {
	cfg := embed.NewConfig()
	srv, _ := embed.StartEtcd(cfg)
	cli := v3client.New(srv.Server)
        // OR cli, _ := clientv3.New(clientv3.Config{Endpoints: []string{"localhost:2379"}})
	cli.KV = namespace.NewKV(cli.KV, "prefix")
}

./etcd_embedded_test.go:63: cannot use cli.KV (type "github.com/coreos/etcdlabs/vendor/github.com/coreos/etcd/clientv3".KV) as type "github.com/coreos/etcd/clientv3".KV in argument to namespace.NewKV:
	"github.com/coreos/etcdlabs/vendor/github.com/coreos/etcd/clientv3".KV does not implement "github.com/coreos/etcd/clientv3".KV (wrong type for Compact method)
		have Compact("github.com/coreos/etcdlabs/vendor/golang.org/x/net/context".Context, int64, ..."github.com/coreos/etcdlabs/vendor/github.com/coreos/etcd/clientv3".CompactOption) (*"github.com/coreos/etcdlabs/vendor/github.com/coreos/etcd/clientv3".CompactResponse, error)
		want Compact("golang.org/x/net/context".Context, int64, ..."github.com/coreos/etcd/clientv3".CompactOption) (*"github.com/coreos/etcd/clientv3".CompactResponse, error)
./etcd_embedded_test.go:63: cannot use namespace.NewKV(cli.KV, "prefix") (type "github.com/coreos/etcd/clientv3".KV) as type "github.com/coreos/etcdlabs/vendor/github.com/coreos/etcd/clientv3".KV in assignment:
	"github.com/coreos/etcd/clientv3".KV does not implement "github.com/coreos/etcdlabs/vendor/github.com/coreos/etcd/clientv3".KV (wrong type for Compact method)
		have Compact("golang.org/x/net/context".Context, int64, ..."github.com/coreos/etcd/clientv3".CompactOption) (*"github.com/coreos/etcd/clientv3".CompactResponse, error)
		want Compact("github.com/coreos/etcdlabs/vendor/golang.org/x/net/context".Context, int64, ..."github.com/coreos/etcdlabs/vendor/github.com/coreos/etcd/clientv3".CompactOption) (*"github.com/coreos/etcdlabs/vendor/github.com/coreos/etcd/clientv3".CompactResponse, error)
FAIL	github.com/coreos/etcdlabs/lru [build failed]

Without vendoring, same code runs fine.
Just open this for reference, if anyone faces the same issue.

[tfzxyinhao]

@gyuho
I have the same problem

[heyitsanthony]

This is blocked on grpc since it's still using /x/net/context. Supposedly go 1.9 will fix this with aliases?

[gyuho]

@tfzxyinhao Do you have example snippet to reproduce? Turns out I did not vendor clientv3/namespace correctly. After vendoring it, the code compiles fine. Other context import issues should be resolved with Go 1.9 type alias (e.g. https://go-review.googlesource.com/c/35671/2/context/go19.go)