In Ubuntu 12.04 LTS I get the following error whenever I use the File->Open Containing Folder feature.
Could not open the containing folder.
Failed to execute child process "pcmanfm" (Permission denied)
This is precisely bug #864992, but for LXDE instead of Gnome.
The problem is fixed for LXDE (and presumably KDE and XFCE) by replacing "/usr/bin/nautilus Cx -> sanitized_helper" with the following to /etc/apparmor.d/usr.bin.evince
/usr/bin/nautilus Cx -> sanitized_helper, #Gnome File Manager
/usr/bin/pcmanfm Cx -> sanitized_helper, #LXDE File Manager
/usr/bin/krusader Cx -> sanitized_helper, #KDE File Manager
/usr/bin/thunar Cx -> sanitized_helper, #XFCE File Manager
(and then running: "sudo /etc/init.d/apparmor reload")
As with bug #864992 the chance of a regression is low, and it should not increase the attack surface in the slightest unless pcmanfm, krusader or thunar were installed (they wouldn't exist in a default Ubuntu install, unless the user manually installed them, in which case the user probably wants to be allowed to use them).
ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: evince-common 3.4.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-26.41-generic 3.2.19
Uname: Linux 3.2.0-26-generic i686
ApportVersion: 2.0.1-0ubuntu8
Architecture: i386
Date: Tue Jul 10 20:40:45 2012
InstallationMedia: Lubuntu 12.04 "Precise Pangolin" - Release i386 (20120423)
PackageArchitecture: all
ProcEnviron:
TERM=xterm
SHELL=/bin/bash
PATH=(custom, user)
LANG=en_AU.UTF-8
LANGUAGE=en_AU:en
SourcePackage: evince
UpgradeStatus: No upgrade log present (probably fresh install)
mtime.conffile..etc.apparmor.d.usr.bin.evince: 2012-07-10T20:40:30.549025
Thank you for your bug report, that seems apparmor related indeed