AptUpgrade() TypeError

[jessebobrien]

example.py fails with a TypeError

[OK]
checking: CommandReq grep -q "deb http://download.virtualbox.org/virtualbox/debian precise non-free contrib" /etc/apt/sources.list||
echo "deb http://download.virtualbox.org/virtualbox/debian precise non-free contrib" >> /etc/apt/sources.list
executing command: grep -q "deb http://download.virtualbox.org/virtualbox/debian precise non-free contrib" /etc/apt/sources.list||
echo "deb http://download.virtualbox.org/virtualbox/debian precise non-free contrib" >> /etc/apt/sources.list
[OK]
Traceback (most recent call last):
File "example.py", line 39, in
AptUpgrade(),
File "/home/jobrien/Development/bork/bork/base_req.py", line 44, in satisfy
satisfy_deps(self.deps, make_satisfied=True)
File "/home/jobrien/Development/bork/bork/base_req.py", line 5, in satisfy_deps
print 'checking: %s' % dep
File "/home/jobrien/Development/bork/bork/apt_reqs.py", line 64, in str
return "AptReq with packages %s " % ', '.join(self.packages) + self.deps_str()
TypeError