Comment 3 for bug 873239

I just have this too with Linux Mint 17.1 Cinnamon DVD.

My crash:
/***
Jan 28 06:33:13 mint ubiquity:
Jan 28 06:33:14 mint /plugininstall.py: Exception during installation:
Jan 28 06:33:14 mint /plugininstall.py: Traceback (most recent call last):
Jan 28 06:33:14 mint /plugininstall.py: File "/usr/lib/ubiquity/ubiquity/install_misc.py", line 287, in pulse
Jan 28 06:33:14 mint /plugininstall.py: self.db.progress('SET', int(self.percent))
Jan 28 06:33:14 mint /plugininstall.py: File "/usr/lib/python3/dist-packages/debconf.py", line 62, in <lambda>
Jan 28 06:33:14 mint /plugininstall.py: lambda *args, **kw: self.command(command, *args, **kw))
Jan 28 06:33:14 mint /plugininstall.py: File "/usr/lib/python3/dist-packages/debconf.py", line 67, in command
Jan 28 06:33:14 mint /plugininstall.py: self.write.flush()
Jan 28 06:33:14 mint /plugininstall.py: BrokenPipeError: [Errno 32] Broken pipe
Jan 28 06:33:14 mint /plugininstall.py:
Jan 28 06:36:21 mint dbus[934]: [system] Activating service
****/

This seems to (have been) a known bug affecting AMD Athlon XP 2600+ to 2800+
Mine is a 2700+
As can be seen on Bug #710582 :
https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/710582
People was saying that removing slideshow package (on XUbuntu or Kubuntu) prior to installing was fixing problem.
Not tried it.
Seems they did (supposedly) resolved it in webkit (I can only suppose slideshow use webkit).

Now, because of my graphics card I am in fallback mode... and I am not sure it did not trigger the bug:
in install_misc.py in pulse function near:
        try:
            if os.environ['UBIQUITY_FRONTEND'] != 'debconf_ui':
                self.db.progress('SET', int(self.percent))
        except debconf.DebconfError:
            return False

I have seen also, still not resolved bug:
I consider bug #1309340 linked
https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1309340