"ERROR No secret key available" on keybase pgp sign

I recently upgraded from pre version 1.0 keybase (prior to the move from keybase sign -> keybase pgp sign) to keybase 1.0.3 on OSX (via brew). I am no longer able to sign messages.

$: echo "hello" | keybase pgp encrypt
-----BEGIN PGP MESSAGE-----
Comment: https://keybase.io/download
Version: Keybase Go 1.0.3 (darwin)
...

$: echo "hello" | keybase pgp sign
ERROR No secret key available

$: gpg -K
--------------------------------
sec   4096R/CEE93F68 2014-09-22 [expires: 2016-09-10]
...
ssb   4096R/07E75F2C 2014-09-22

$: gpg --edit-key CEE93F68
gpg (GnuPG/MacGPG2) 2.0.28; Copyright (C) 2015 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Secret key is available.

pub  4096R/CEE93F68  created: 2014-09-22  expires: 2016-09-10  usage: SC  
                     trust: ultimate      validity: ultimate
sub  4096R/07E75F2C  created: 2014-09-22  expires: 2016-09-10  usage: E 
...

The odd thing here is keybase is clear associated with my master key, I can use the subordinate key to encrypt, but I can't use the master key to sign?

I can also use the gpg tools to sign without issue:

$: echo "hello" | gpg --sign --armour
-----BEGIN PGP MESSAGE-----
Comment: GPGTools - https://gpgtools.org
...

Start by reproducing the failure with echo "hello" | keybase pgp sign, then compare the key details from gpg -K and gpg --edit-key CEE93F68 with the successful encryption and GPG signing commands. Done means Keybase can sign the same message with the available secret key on the reported macOS setup.