`keybase login` produces unexpected password prompt for "GPG commands" option

I attempted to use keybase login for the first time on Debian 7 with version 1.0.9-1 using the GPG commands signing option. Here's the transcript, with email addresses elided to slightly delay the spampocalypse:

$ keybase login
How would you like to sign this install of Keybase?

(1) Use an existing device
(2) Use a paper key
(3) Use my Keybase passphrase
(4) Use GPG
Choose a signing option: 4
In order to authorize this installation, keybase needs to sign this installation
with your GPG secret key.

You have two options.

(1) Keybase can use GPG commands to sign the installation.

(2) Keybase can export your secret key from GPG and save it to keybase's local encrypted
    keyring. This way, it can be used in 'keybase pgp sign' and 'keybase pgp decrypt' 
    going forward.
Which do you prefer?: 1
#    Algo   Key Id             Created      UserId
=    ====   ======             =======      ======
1    D      550354173BBF4E12   2006-09-16   Timothy W. McCormack <...>
Choose a key: 1

After a second I am presented with a pinentry window asking "Please enter the Keybase passphrase for timmc". I am startled, so I close it and am presented with:

▶ ERROR Input canceled

Is this expected? It certainly seems like keybase is defaulting to passphrase signing. Alternatively, what's the point of the GPG option if I need the keybase.io passphrase anyhow?

Bonus

The very first time I ran this, after selecting the GPG key I got this error instead of a pinentry dialog:

▶ ERROR API network error: Get https://keybase.io/_/api/1.0/key/basics.json?fingerprint=c669006ed00822ba968f799d550354173bbf4e12: dial tcp: lookup keybase.io on 192.168.1.1:53: read udp 192.168.1.132:47996->192.168.1.1:53: i/o timeout (error 1601)

Start by reproducing keybase login version 1.0.9-1 on Debian 7, selecting GPG and then the GPG commands option with the listed key. Compare the resulting pinentry prompt and cancellation with the expected GPG signing flow, and separately account for the reported keybase.io network timeout. Done means the prompt behavior is explained or corrected and the GPG option's expected requirements are clear.