su-to-root -X -c bleachbit: Could not open X display

I cannot reproduce on Ubuntu 12.10 with BleachBit 0.9.3 installed from the Ubuntu repository.

Are you using KDE, GNOME, Ubuntu Unity, or something else?

Do you have a file ~/.gtkrc-2.0 ? What is in it?

From https://bbs.archlinux.org/viewtopic.php?pid=999078#p999078

I made login on "Ubuntu classic (no effects)"
---------------------------------------------------------------
The .gtkrc-2.0 content: cat .gtkrc-2.0

include "/usr/share/themes/oxygen-gtk/gtk-2.0/gtkrc"

gtk-theme-name="oxygen-gtk"

---------------------------------------------------------------
also the .gtkrc-2.0-kde4 content

# This file was written by KDE
# You can edit it in the KDE control center, under "GTK Styles and Fonts"

include "/usr/share/themes/Radiance/gtk-2.0/gtkrc"

style "user-font"
{
 font_name="Ubuntu"
}
widget_class "*" style "user-font"

gtk-theme-name="Radiance"
gtk-font-name="Ubuntu 9"

---------------------------------------------------------------

echo $DISPLAY
:0.0

With this command

gksudo -k bleachbit

bleachbit is work as root

I think this problem is in GTK or su-to-root

Just installed Kubuntu 12.10 AMD64 desktop

get same problem trying to run bleacbit as root
gksudo -k bleachbit did not work - did get error message:
Error copying '/tmp/kde-jay/xauth-1000-_0' to '/tmp/libgksu-db2kSu': No such file or directory

but, in /tmp is:
drwx------ 2 jay jay 4096 Mar 12 18:45 libgksu-db2kSu
in there is
-rw------- 1 jay jay 0 Mar 12 18:45 .Xauthority

note: zero-length.
and /tmp/kde-jay is empty.

nothing interestin in /var/log/Xorg.0.log
no errors in /var/log/auth.log

weird message in syslog
Mar 12 18:53:45 pc-14-large dbus[780]: [system] Activating service name='org.kde.powerdevil.backlighthelper' (using servicehelper)
Mar 12 18:53:45 pc-14-large org.kde.powerdevil.backlighthelper: QDBusConnection: system D-Bus connection created before QCoreApplication. Application may misbehave.
Mar 12 18:53:45 pc-14-large dbus[780]: [system] Successfully activated service 'org.kde.powerdevil.backlighthelper'
Mar 12 18:55:00 pc-14-large dbus[780]: [system] Activating service name='org.kde.powerdevil.backlighthelper' (using servicehelper)
Mar 12 18:55:00 pc-14-large org.kde.powerdevil.backlighthelper: QDBusConnection: system D-Bus connection created before QCoreApplication. Application may misbehave.
Mar 12 18:55:00 pc-14-large dbus[780]: [system] Successfully activated service 'org.kde.powerdevil.backlighthelper'

hope this helps.
Jay

On KDE (KUbuntu) I solved this problem via adding the following files to bleachbit's white list:

/tmp/kde-chapaikinva/xauth-1000-_0
/home/chapaikinva/.kde/tmp-AP35-2008/xauth-1000-_0

where:

"chapaikinva" - is my username in ubuntu,
"1000" - is code for my ubuntu user's account,
"AP35-2008" - is my computer's name.

I think this is a duplicate of bug 1377719. There is more info there.