Unable to find/read gz files

Looks like ureadahead is unable to read compressed (gz) files.

From journalctl:
 ureadahead[300]: ureadahead:/home/oem/.cache/upstart/upstart-event-bridge.log: No such file or directory
 ureadahead[300]: ureadahead:/home/oem/.cache/upstart/gnome-keyring-ssh.log: No such file or directory
 ureadahead[300]: ureadahead:/home/oem/.cache/upstart/click-user-hooks.log: No such file or directory
 ureadahead[300]: ureadahead:/home/oem/.cache/upstart/ssh-agent.log: No such file or directory
 ureadahead[300]: ureadahead:/home/oem/.cache/upstart/window-stack-bridge.log: No such file or directory
 ureadahead[300]: ureadahead:/home/oem/.cache/upstart/at-spi2-registryd.log: No such file or directory
 ureadahead[300]: ureadahead:/home/oem/.hplip/hp-systray.lock: No such file or directory

The latest files created since the latest cold boot:
 ls -l ~/.cache/upstart/
total 44
-rw-r----- 1 oem oem 224 Mar 12 14:03 at-spi2-registryd.log.1.gz
-rw-r----- 1 oem oem 57 Mar 12 14:03 click-user-hooks.log.1.gz
-rw-r----- 1 oem oem 483 Mar 12 14:22 dbus.log
-rw-r----- 1 oem oem 415 Mar 12 14:04 dbus.log.1.gz
-rw-r----- 1 oem oem 99 Mar 12 14:03 gnome-keyring-ssh.log.1.gz
-rw-r----- 1 oem oem 549 Mar 12 14:29 gnome-settings-daemon.log
-rw-r----- 1 oem oem 989 Mar 12 14:03 gnome-settings-daemon.log.1.gz
-rw-r----- 1 oem oem 60 Mar 12 14:03 ssh-agent.log.1.gz
-rw-r----- 1 oem oem 72 Mar 12 14:03 update-notifier-release.log.1.gz
-rw-r----- 1 oem oem 68 Mar 12 14:03 upstart-event-bridge.log.1.gz
-rw-r----- 1 oem oem 143 Mar 12 14:03 window-stack-bridge.log.1.gz

So some files are compressed (.log.1.gz), and some not. Wonder about the real needs to set them compressed.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ureadahead 0.100.0-19
ProcVersionSignature: Ubuntu 4.4.0-13.29-generic 4.4.5
Uname: Linux 4.4.0-13-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_modeset nvidia
ApportVersion: 2.20-0ubuntu3
Architecture: amd64
CurrentDesktop: GNOME
Date: Sat Mar 12 14:24:58 2016
PackDump: Error: command ['ureadahead', '--dump'] failed with exit code 4: ureadahead:/var/lib/ureadahead/pack: Permission denied
SourcePackage: ureadahead
UpgradeStatus: No upgrade log present (probably fresh install)