For now, "incubator membership" means a subscription to the Telemetry mailing list. You'll need (and want) to join the list to participate. Once you've joined the list, just use your mailman subscription address and password to log into Trac here.

See the bottom of the list info page if you don't remember your list password. If you've forgotten both your password and your subscription address, then you'll need to look for the reminder message that is sent out from mailman.terraluna.org once a month.

Standard disclaimers apply -- I don't have mailman or Trac set up with SSL certs at this time, so you'll want to use a cheap and disposable password. The Trac code (as of 0.8) has a habit of showing your e-mail address as the default username in ticket entry and Wiki edit forms; a mild pain if you're doing a lot of editing and trying to keep your address secret. I'm one of those people who lets the world know my address, so it doesn't bother me as much.