configure: error: No working boost sleep implementation found
Found the problem. Had these lines in my .bashrc and commenting them out fixed it:



alias gcc="gcc-8"
alias g++="g++-8"
export CC="gcc"
export CXX="/usr/bin/gcc-8"
export PATH=/usr/local/clang_8.0.0/bin:$PATH
export LD_LIBRARY_PATH=/usr/local/clang_8.0.0/lib:$LD_LIBRARY_PATH


Why this caused ./configure to error out, I have no idea. But problem solved.