Using Fabric, When put() is called, some files are failing upload with size mismatch.

I'm trying to upload simple text file to a remote server
and it fails

Using Python 2.7
Paramiko 2.4.0 (from within Fabric)
On Mac OSX Sierra
To (target machine): Ubunto 14.04 on Amazon EC2

Other templates pass, so there is some kind of an inconsistency.

Warning: put() encountered an exception while uploading '<StringIO.StringIO instance at 0x105ef15a8>'

Traceback (most recent call last):
  File "/Users/ccc/.virtualenvs/py2.7/lib/python2.7/site-packages/fabric/operations.py", line 399, in put
    mode, local_is_path, temp_dir)
  File "/Users/xxx/.virtualenvs/py2.7/lib/python2.7/site-packages/fabric/sftp.py", line 256, in put
    rattrs = putter(local_path, remote_path)
  File "/Users/xxx/.virtualenvs/py2.7/lib/python2.7/site-packages/paramiko/sftp_client.py", line 692, in putfo
    'size mismatch in put!  {} != {}'.format(s.st_size, size))
IOError: size mismatch in put!  16753 != 16747

Start with paramiko/sftp_client.py at the putfo() call shown in the traceback, then reproduce the upload through Fabric using the reported StringIO input. Compare the local and remote sizes involved in the check and review the existing issue comments for context. Done means the reported upload no longer produces a size mismatch and the behavior is covered by an appropriate regression test.