golang martini session.Set not setting any value

There isn't much context with this because it really is a situation where something should work, but it just doesn't.

I am using the martini framework. In one handler I'm using this:

session.Set("deployed", "true")
r.Redirect("/myOtherURL", http.StatusSeeOther)

Whereby 'session' is the sessions.Session object passed through to the handler.
In the handler that loads myOtherURL, I'm using session.Get but nothing is being returned. I printed out all of the session content and the 'deployed' is not present.

What could be causing this problem? What could I possibly be missing out? I would give more context if I could but it really is as simple as this.

Just to extend on my comment/help others in the future:

• When you set a cookie without an explicit Path value, the cookie takes on the current path.
• Cookies are only sent for that path and paths below - not above - e.g.

1. Cookie set for /modules when you implicitly set it for the first time via session.Set(val, key)
2. Cookie is sent for /modules, /modules/all and /modules/detail/12
3. Cookie is NOT sent for /about or /

This can be fixed by explicitly setting the path:

var store = sessions.NewCookieStore([]byte("secret123"))

func main() {
    store.Options.Path = "/"
    ...
}

Be aware that you may not want to send a cookie for all routes (which is what / will do) - so use judgement.