add more logging, and report an error if we can't find the extracted file. Fixes #235

Hello @dpup, 

Please review the following commits I made in branch 'nick-copy'.

9cc69ef7ab6ad1d2f014d20ae8a0b3db73248a9e (2014-10-16 11:50:25 -0400)
add more logging, and report an error if we can't find the extracted file. Fixes #235

R=@dpup