/usr/share/boost-build/src/build/ is in libboost1.62-tools-dev 1.62.0+dfsg-5.
This file is owned by root:root, with mode 0o755.
..
/usr/share/boost-build/src/build/ac.jam
/usr/share/boost-build/src/build/alias.jam
/usr/share/boost-build/src/build/alias.py
/usr/share/boost-build/src/build/build-request.jam
/usr/share/boost-build/src/build/build_request.py
/usr/share/boost-build/src/build/config-cache.jam
/usr/share/boost-build/src/build/configure.jam
/usr/share/boost-build/src/build/configure.py
/usr/share/boost-build/src/build/engine.py
/usr/share/boost-build/src/build/errors.py
/usr/share/boost-build/src/build/feature.jam
/usr/share/boost-build/src/build/feature.py
/usr/share/boost-build/src/build/generators.jam
/usr/share/boost-build/src/build/generators.py
/usr/share/boost-build/src/build/project.ann.py
/usr/share/boost-build/src/build/project.jam
/usr/share/boost-build/src/build/project.py
/usr/share/boost-build/src/build/property-set.jam
/usr/share/boost-build/src/build/property.jam
/usr/share/boost-build/src/build/property.py
/usr/share/boost-build/src/build/property_set.py
/usr/share/boost-build/src/build/scanner.jam
/usr/share/boost-build/src/build/scanner.py
/usr/share/boost-build/src/build/targets.jam
/usr/share/boost-build/src/build/targets.py
/usr/share/boost-build/src/build/toolset.jam
/usr/share/boost-build/src/build/toolset.py
/usr/share/boost-build/src/build/type.jam
/usr/share/boost-build/src/build/type.py
/usr/share/boost-build/src/build/version.jam
/usr/share/boost-build/src/build/version.py
/usr/share/boost-build/src/build/virtual-target.jam
/usr/share/boost-build/src/build/virtual_target.py