/usr/bin/scan-build-3.9 is in clang-3.9 1:3.9.1-19ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/bin/../share/clang/scan-build-3.9/bin/scan-build
/usr/bin/../share/clang/scan-build-3.9/bin/scan-build