levelBug.js

var level = require("levelup");
var sublevel = require("level-sublevel");

var db = sublevel(level("/tmp/buuuug"));
var sub = db.sublevel("gh");

sub.put("key", "value", function() {
  var emitted = 0;
  sub.createReadStream()
    .on("data", function(data) {
      emitted++;
      console.log(data);
     })
    .on("close", function() {
      if (emitted === 0) {
        console.log("failed");
        process.exit(1);
      } else {
        console.log("succeeded");
      }
     });
});

package.json

{
  "name": "sublevel-bug",
  "version": "0.0.0",
  "description": "",
  "scripts": {
    "test": "node levelBug.js"
  },
  "author": "",
  "license": "BSD",
  "dependencies": {
    "level-sublevel": "~4.8.0",
    "levelup": "~0.12.0",
    "leveldown": "~0.6.2"
  }
}