boto/boto — pull request #1082 by petertodd (2012-10-26 19:53:08+00:00)
Title: Glacier: Raise exception on attempt to upload an empty archive 

Currently you get a weird failure in tree_hash() instead:

Traceback (most recent call last):

File "/home/pete/src/glacier-cli/boto/glacier/writer.py", line 65, in tree_hash
return hashes[0]
IndexError: list index out of range

Amazon does not allow empty archives to be uploaded, so raising an exception specific to this error is correct.

FWIW I've also written a (much uglier) patch for glacier-cli to allow you to fake uploads of empty archives so git-annex works.