Distributor ID: Ubuntu
Description:    Ubuntu 13.04
Release:        13.04
Codename:       raring

dist-upgrade fails because there is not enough space on /boot.
UI cannot report it because it cannot find apport.
apport cannot be found because it is installed on another version of than the default.
Python is:
$> ls -l /usr/bin/python
lrwxrwxrwx 1 root root 9 heinä  3 21:34 /usr/bin/python -> python2.7
$>
$> python2.7 
Python 2.7.4 (default, Sep 26 2013, 03:20:26) 
[GCC 4.7.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import apport
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named apport
$> python3.3
Python 3.3.1 (default, Sep 25 2013, 19:29:01) 
[GCC 4.7.3] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import apport
>>> 
$> 

Reproducible: Always

Steps to Reproduce:
1. start Update Manager
2. press Upgrade
3. wait
Actual Results:  
after fetching the packages upgrader ui just disappears. 
only logs show that something failed

Expected Results:  
a. upgrade runs until finished
b. error is reported on the UI

from /var/log/dist-upgrade/20131106-1312/main.log

.....
2013-11-06 13:00:06,362 ERROR Not enough free space: ['/boot']
2013-11-06 13:00:06,363 ERROR not handled exception in KDE frontend:
Traceback (most recent call last):

  File "/tmp/ubuntu-release-upgrader-ftj2y2/saucy", line 10, in <module>
    sys.exit(main())

  File "/tmp/ubuntu-release-upgrader-ftj2y2/DistUpgrade/DistUpgradeMain.py", line 243, in main
    if app.run():

  File "/tmp/ubuntu-release-upgrader-ftj2y2/DistUpgrade/DistUpgradeController.py", line 1791, in run
    return self.fullUpgrade()

  File "/tmp/ubuntu-release-upgrader-ftj2y2/DistUpgrade/DistUpgradeController.py", line 1744, in fullUpgrade
    if not self.askDistUpgrade():

  File "/tmp/ubuntu-release-upgrader-ftj2y2/DistUpgrade/DistUpgradeController.py", line 978, in askDistUpgrade
    if not self._checkFreeSpace():

  File "/tmp/ubuntu-release-upgrader-ftj2y2/DistUpgrade/DistUpgradeController.py", line 955, in _checkFreeSpace
    required.dir))

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2 in position 1: ordinal not in range(128)

2013-11-06 13:00:06,363 DEBUG running apport_crash()
2013-11-06 13:00:06,363 ERROR failed to import apport python module, can't report bug: No module named apport_python_hook
2013-11-06 13:00:06,363 DEBUG can't find apport
2013-11-06 13:00:06,368 DEBUG enabling apt cron job
(END)