"--enable-dbus: enable basic D-BUS and D-BUS Murphy transport support. If you need D-BUS support, for instance for data collection, you need this. Note that this option also requires --enable-gpl and will cause the resulting binaries to be distributable under the GPLv2.1 license."
Quote from https://01.org/murphy/documentation/compiling-and-installing-murphy
"--enable-dbus: enable basic D-BUS and D-BUS Murphy transport support. If you need D-BUS support, for instance for data collection, you need this. Note that this option also requires --enable-gpl and will cause the resulting binaries to be distributable under the GPLv2.1 license."
It's GPLv2, not GPLv2.1.