Merge pull request moby#5738 from crazy-max/dockerfile-device-error-n…

…olabs

dockerfile: error out if device feature not used in labs

frontend/dockerfile/dockerfile2llb/convert_norundevice.go

@@ -5,8 +5,12 @@ package dockerfile2llb
 import (
 	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/frontend/dockerfile/instructions"
+	"github.com/pkg/errors"
 )
 
-func dispatchRunDevices(_ *instructions.RunCommand) ([]llb.RunOption, error) {
+func dispatchRunDevices(c *instructions.RunCommand) ([]llb.RunOption, error) {
+	if len(instructions.GetDevices(c)) > 0 {
+		return nil, errors.Errorf("device feature is only supported in Dockerfile frontend 1.14.0-labs or later")
+	}
 	return nil, nil
 }