gpg is never asking me for an actual password; can't decrypt key

When trying to use any Keybase feature, I get something like this:

```
> keybase track max
info: ...checking identity proofs
✔ public key fingerprint: 8EFB E2E4 DD56 B352 7363 4E8F 6052 B2AD 31A6 631C
✔ "maxtaco" on twitter: https://twitter.com/maxtaco/status/433688676975927296
✔ "maxtaco" on github: https://gist.github.com/8847250
✔ "maxtaco" on reddit: https://www.reddit.com/r/KeybaseProofs/comments/2clf9c/my_keybase_proof_redditmaxtaco_keybasemax/
✔ "maxtaco" on coinbase: https://coinbase.com/maxtaco/public-key
✔ "maxtaco" on hackernews: https://news.ycombinator.com/user?id=maxtaco
✔ admin of keybase.io via HTTPS: https://keybase.io/.well-known/keybase.txt
✔ admin of oneshallpass.com via HTTPS: https://oneshallpass.com/.well-known/keybase.txt
✔ admin of the DNS zone for oneshallpass.com
✔ admin of the DNS zone for maxk.org
✔ admin of the DNS zone for nutflex.com
Is this the max you wanted? [y/N] y
Permanently track this user, and write proof to server? [Y/n] y

You need a passphrase to unlock the secret key for
user: "elliottcable "
4096-bit RSA key, ID DEADBEEF, created 2014-01-01
(subkey on main key ID F1D0BEEF)
```

At this point, I never get a prompt to actually _type_ my password. The process simply hangs; anything typed is echoed to the terminal.

I'm no GPG initiate; I have no idea what to do here. (If it's relevant, my private-key is stored an a usually-unmounted device.) Any solutions?

Start by reproducing `keybase track max` with the private key available, observing the GPG passphrase step and terminal input behavior. Trace the command's GPG interaction and verify that entering the passphrase is prompted visibly, accepted, and allows the key to be decrypted.

Written by the indexing model from the issue text.