builder-next: support DOCKER_RAMDISK
For
@@ -31,6 +31,7 @@ func newExecutor(root, cgroupParent string, net libnetwork.NetworkController, ro
CommandCandidates: []string{"runc"},
DefaultCgroupParent: cgroupParent,
Rootless: rootless,
+ NoPivot: os.Getenv("DOCKER_RAMDISK") != "",
}, networkProviders)
}
