s3cmd incomplete format error

Question

When I run

$ s3cmd

I get

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    An unexpected error has occurred.
  Please report the following lines to:
   s3tools-bugs@lists.sourceforge.net
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Problem: ValueError: incomplete format
S3cmd:   1.0.1

Traceback (most recent call last):
  File "/usr/bin/s3cmd", line 2006, in <module>
    main()
  File "/usr/bin/s3cmd", line 1795, in main
    cfg = Config(options.config)
  File "/usr/lib/python2.7/site-packages/S3/Config.py", line 88, in __init__
    self.read_config_file(configfile)
  File "/usr/lib/python2.7/site-packages/S3/Config.py", line 105, in read_config_file
    cp = ConfigParser(configfile)
  File "/usr/lib/python2.7/site-packages/S3/Config.py", line 142, in __init__
    self.parse_file(file, sections)
  File "/usr/lib/python2.7/site-packages/S3/Config.py", line 170, in parse_file
    print_value = (data["value"][:2]+"...%d_chars..."+data["value"][-1:]) % (len(data["value"]) - 3)
ValueError: incomplete format

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    An unexpected error has occurred.
    Please report the above lines to:
   s3tools-bugs@lists.sourceforge.net
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

anyone any ideas ??

Answer 1

I found out where is the problem.

I was configuring s3cmd over s3cmd --config

s3cmd had asked me to set up encrypted passphraze/password for GPG

$ s3cmd --configure
...
Encryption password is used to protect your files from reading
by unauthorized persons while in transfer to S3
Encryption password 

I had set up really strong password including non A-Z chars (as %). s3cmd --configure didn't escape thos chars, therefore my configuration file was generated like this:

cat ~/.s3cfg
...
gpg_passphrase = examplepassword123%%
...

if anyone else have this kind of problem: to solve this remove s3cmd config file and run config again and set up password/passpraze with a-z A-Z 0-9 chars only

 rm ~/.s3cfg
 s3cmd --configure