/usr/include/d/ is in libdcontainers-dev 0.8.0~alpha.6-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/d/containers/
/usr/include/d/containers/containers/
/usr/include/d/containers/containers/cyclicbuffer.d
/usr/include/d/containers/containers/dynamicarray.d
/usr/include/d/containers/containers/hashmap.d
/usr/include/d/containers/containers/hashset.d
/usr/include/d/containers/containers/immutablehashset.d
/usr/include/d/containers/containers/internal/
/usr/include/d/containers/containers/internal/backwards.d
/usr/include/d/containers/containers/internal/element_type.d
/usr/include/d/containers/containers/internal/hash.d
/usr/include/d/containers/containers/internal/mixins.d
/usr/include/d/containers/containers/internal/node.d
/usr/include/d/containers/containers/internal/storage_type.d
/usr/include/d/containers/containers/openhashset.d
/usr/include/d/containers/containers/package.d
/usr/include/d/containers/containers/simdset.d
/usr/include/d/containers/containers/slist.d
/usr/include/d/containers/containers/treemap.d
/usr/include/d/containers/containers/ttree.d
/usr/include/d/containers/containers/unrolledlist.d