Keybase verify does not work properly but decrypting says "Valid signature from you"

I encrypted a file, let's call it `test.txt` with the data "this is a test\n" using the following command:

`keybase encrypt -s myusername test.txt`

... which output the file `test.txt.asc`. If I run the command `keybase decrypt test.txt.asc`, it outputs:

this is a test
info: Valid signature from you
info: Signed less than a minute ago (Thu Sep 25 2014 08:19:23 GMT-0700 (PDT))

... but if I run `keybase verify test.txt.asc` I get the output:

warn: [GNUPG:] UNEXPECTED 0
warn: gpg: verify signatures failed: Unexpected error
error: `gpg` exited with code 2

Reproduce the issue with the documented `keybase encrypt`, `keybase decrypt`, and `keybase verify` commands using a small text file, then compare the decrypt and verify outputs. Trace how signature verification is handled when decrypting versus verifying; done means `keybase verify test.txt.asc` recognizes the signature without the reported GnuPG error.

索引モデルが issue の本文から書いたものです。