build failed for me. Please let me know if you find a way around it.
/home/user/src/graphene/libraries/plugins/witness/witness.cpp:229:10: note: in expansion of macro ‘elog’
elog("Not producing block because node appears to be on a minority fork with only ${pct}% witness participation", (capture) );
^
make[2]: *** [libraries/plugins/witness/CMakeFiles/graphene_witness.dir/witness.cpp.o] Error 1
make[1]: *** [libraries/plugins/witness/CMakeFiles/graphene_witness.dir/all] Error 2
make: *** [all] Error 2
user@user-desktop:~/src/graphene$