[PATCH 1 of 2] bundle2: add some debugging information to the not-a-bundle error

[Yuya Nishihara]

On Tue, 27 Jun 2017 14:38:42 -0700, Siddharth Agarwal wrote:
> # HG changeset patch
> # User Siddharth Agarwal <sid0 at fb.com>
> # Date 1498599055 25200
> #      Tue Jun 27 14:30:55 2017 -0700
> # Node ID 8b59a6d6f77927cc7b40b282056278829ca398b3
> # Parent  eb4c49f55f1f0d7719f514c16bec54515eb54f62
> bundle2: add some debugging information to the not-a-bundle error

Queued, thanks.