Output in terminal emulator:

ERROR:proctable.cpp:135:void proctable_set_columns_order(GtkTreeView*, GSList*): assertion failed: (id >= 0 && id < NUM_COLUMNS)
Aborted

There was "Automatic". I also tried SMplayer & here is log from it: /usr/bin/mplayer -noquiet -slave -identify -nofs -lavdopts skiploopfilter=all:threads=2 -sub-fuzziness 1 -vo xv -ao alsa -nodr -double -stop-xscreensaver -nomouseinput -input nodefault-bindings:conf=/dev/null -nokeepas...

VLC installed from Gslapt. Output from VLC in terminal emulator [mpeg2video @ 0xb2a6b4e0] 00 motion_type at 9 20 [mpeg2video @ 0xb2a6b4e0] invalid mb type in B Frame at 25 20 [mpeg2video @ 0xb2a6b4e0] 00 motion_type at 13 21 [mpeg2video @ 0xb2a6b4e0] mb incr damaged [mpeg2video @ 0xb2a6b4e0] 00 moti...

Thanks. I also using Synapse & Zeitgeist. Tried to install Synapse but no luck. Instead I have installed your packages.

And if I do not want a full Slackware install because I do need all that?

The same. I have deleted ~/gPodder & ~/.config/gpodder directories & it`s helped.

Response from maintainer:

Hi,

A full Slackware install is required for all packages on slackbuilds.org (https://slackbuilds.org/faq/#full). Ruby is one of the many packages included with Slackware. I won't be adding Ruby to the REQUIRES line.

qt 5.5.1. There was no Ruby listed as dependency in slackbuild description.

I have found this discussion in which user writes about Ruby interpreter as missing dependency. Using tee, the SlackBuild output shows that WebKit is never built due to a missing dependency: The WebKit build was disabled for the following reasons: * Missing ruby from PATH I used to have ruby install...

After a couple hours of compiling it fails with this: I tried to search for Qt5WebKit.pc and can`t find it.