Error: Failed to serialize user into session. Possible lack of support for redis session store?

I'm using a redis session store and I'm combining both FacebookStrategy and LocalStrategy (I hope I can?). I have passport setup like this:

```
var express = require('express')();
var router = express.Router();
router.use(passport.initialize());
router.use(passport.session());

var redisSessionStore = redisClient.redisSessionStore;
P.promisifyAll(redisClient.redisSessionStore);

var sess = {
store: redisSessionStore,
secret: 'secret',
cookie: {
expires: false,
}
}

express.use(session(sess));

module.exports = passport.use(new FacebookStrategy({
clientID: config.facebook.clientID,
clientSecret: config.facebook.clientSecret,
callbackUrl: config.facebook.callbackUrl
},
function(accessToken, refreshToken, profile, done) {
// validate user existence or create new one.
process.nextTick(function () {
console.log(accessToken);
console.log(profile);
return done(null, profile);
});
}
));
module.exports = passport.use(new LocalStrategy(
function(username, password, done) {
console.log('authenticating: ' + username);
var user = {
_id: 1,
username: 'mari',
password: 'alako'
};
return done(null, user);
}
));

passport.serializeUser(function(user, done) {
console.log('serializeUser: ' + user._id)
done(null, user._id);
});
passport.deserializeUser(function(id, done) {
var user = {
_id: 1,
username: 'mari',
password: 'alako'
};
done(null, user);
});

// login route with passport
router.post('/userlogin', bodyParser.text({ type: 'urlencoded' }), function(req, res, next) {
passport.authenticate('local', function(err, user, info) {
console.log('Retrieved User is: ' + JSON.stringify(user));
req.logIn(user, function(err){
if (err) { return next(err); }
console.log('passport: ' + user.username + ' is logged in ');
});
})(req, res, next);
res.send('authenticating with passport');
});
```

The issue names no repository files or tests; begin with the middleware, Redis session configuration, and serializeUser usage shown in the report. Reproduce the local login flow with the Redis store and both strategies, then trace the serialization error. Done means the reported login succeeds without the session serialization failure.

Written by the indexing model from the issue text.