25 October 2016

Fixing PackageKit authentication in Debian sid under Xfce

Today after updating stuff, my pkexec commands (e.g., synaptic-pkexec) stopped working. I don't know whether this was caused by something I inadvertently did that borked things or whether it's a bug in Debian sid. I figured out that the root of the problem (no pun intended) is that a policy authentication agent was no longer loading on login -- in spite of policykit-1-gnome being installed and the entry for PolicyKit Authentication agent being checked in Xfce's Session and Startup autostarts.

Reinstalling stuff didn't help.

Further sleuthing revealed that the PolicyKit Authentication agent entry in Xfce's Session and Startup was pointing to a (now) nonexistent file: /usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1. Further examination revealed that the file /etc/xdg/autostart/polkit-gnome-authentication-agent-1.desktop installed by policykit-1-gnome also was pointing to the same nonexistent file.

So here's what I did to kludge a fix:
  • Created a new directory /usr/lib/policykit-1-gnome
  • Added a link from /usr/lib/x86_64-linux-gnu/polkit-gnome-authentication-agent-1 to /usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1.
After logging out and back in, things worked as expected.

I could have added a custom entry into my Xfce autostarts that pointed to the correct file, but that wouldn't have addressed the second issue of /etc/xdg/autostart/polkit-gnome-authentication-agent-1.desktop pointing to phantoms.

To undo the changes once/if the problem is better sorted, all I need to do is delete /usr/lib/policykit-1-gnome.

28 May 2016

Fixing virtual console resolution with nVidia driver

I tried a number of things to get a laptop with an nVidia GT218M [NVS 3100M] video card to provide decent resolution in virtual consoles. This particular unit needs to run the proprietary video drivers to behave well--the big exception being the big-and-fuzzy virtual terminal text.

What finally worked for me in /etc/default/grub was

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)

# Uncomment to disable graphical terminal (grub-pc only)

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux

# Uncomment to disable generation of recovery mode menu entries

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"
The important parts are the GRUB_GFXMODE=1600x900 and GRUB_GFXPAYLOAD_LINUX=keep lines.

Don't forget to
$ update-grub
Credit goes to StackExchange.

01 May 2016

Adding "Run" options to Thunar

 Clicking on executable shell files no longer executes them in Thunar.

While there is a hidden option to revert to the old behavior, I decided in a new install to instead add right menu "Run" and "Run in terminal" custom actions. First create the custom actions from within Thunar to get valid unique-ids, and then open ~/.config/Thunar/uca.xml and edit the entries as needed:

    <command>exec ./&apos;%n&apos;</command>
    <description>Execute this file</description>
    <name>Run in terminal</name>
    <command>xterm -T &apos;%n&apos; -e &quot;./&apos;%n&apos;; echo &apos;&apos;; read -p &apos;Press &lt;Enter&gt; to close...&apos;&quot;</command>
    <description>Execute this file in a terminal</description>

26 April 2016

Concerns about Qt's increasing commercial focus

It's not just me. Phoronix is reporting on growing concerns in the Qt community about the project's increasing commercial focus and apparent deprecation of its open source core.

I have said many times in these pages and elsewhere that I really like Qt: it's the right tool for a lot of jobs. But increasingly I've been feeling that any contribution I make in educating users about Qt is benefiting a commercial enterprise and not a community tool. So much so that I am re-surveying other open source multi-platform libraries to use as an alternative to Qt.

If the community no longer has meaningful Qt ownership, a lot of users will no longer be interested.

25 April 2016

Fixing Debian sid touchpad with libinput

A recent sid update brought in Xorg's libinput package, which appears to make the old way of configuring touchpads (including synclient) obsolete.

One of the issues I had after the update was that my touchpad's tap-to-click stopped working. I fixed this using the info on this Stack Exchange post, namely I created a file
/usr/share/X11/xorg.conf.d/10-touchpad.conf containing:

Section "InputClass"
        Identifier "MyTouchpad"
        MatchIsTouchpad "on"
        Driver "libinput"
        Option "Tapping" "on"

Note the different location from the one in the post. I also disabled the old 50-synaptics.conf, 50-vmmouse.conf, and 51-synaptics-aptosid.conf files (the latter two present possibly only in aptosid).

Apparently, Petter Hutterer has a post that goes into detail regarding what you can do with libinput, but I've not yet had time to read it.

Update (later the same day): With the above changes, my touchpad still had behavioral problems. I'll return to this later, but for now I re-enabled 50-synaptics.conf, 50-vmmouse.conf, and 51-synaptics-aptosid.conf and purged xserver-xorg-input-libinput (which removed xserver-xorg-input-all).