On slackware current, Clementine 1.2.3 has issues with QtWebKit being linked to Gstreamer 1, because during compilation it links itself to Gstreamer 0.10.
Clementine from git release has been integrated with Gstreamer 1 compatibility.
make dependencies are:
protobuf i486, x86_64
libspotify i686, x86_64
and libechonest i486, x86_64
This slackbuild will download from git and build the binaries.
This is the SLKBUILD
Before run it download this file and run it to download the code from git.
Clementine binaries (for lazy slackers) i486, x86_64