The taskjuggler and taskjuggler-libs packages are not available for Red Hat Enterprise Linux 7. Upstream stopped supporting TaskJuggler 2, and TaskJuggler 3 written in Ruby is not compatible.
Unfortunately, no replacement is supported by Red Hat. If your processes require these packages, you may either compile the kdelibs 3 and kdepim 3 stack (bringing QT 3 stuff into Red Hat Enterprise Linux 7), or migrate to TaskJuggler 3 (from upstream, at www.taskjuggler.org).
