In order to use the (beta) live tracing features of LttngTop, you need these
branches :

git clone -b lttngtop-live git://git.dorsal.polymtl.ca/~jdesfossez/lttng-tools
git clone -b lttngtop-live git://git.dorsal.polymtl.ca/~jdesfossez/babeltrace

The only difference between these branches and the master branch is that they
export an additional library that is used by lttngtop to do live tracing.

You have to compile and install lttng-tools before babeltrace since there are
dependencies on the library exposed by this special lttng-tools in babeltrace
for live mmap buffer consuming.

Then you can compile and use the live branch of LttngTop :
git clone -b live git://git.lttng.org/lttngtop.git