/usr/include/ is in libtumbler-1-dev 0.1.30-1+b1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/tumbler-1/
/usr/include/tumbler-1/tumbler/
/usr/include/tumbler-1/tumbler/tumbler.h
/usr/include/tumbler-1/tumbler/tumbler-abstract-thumbnailer.h
/usr/include/tumbler-1/tumbler/tumbler-cache.h
/usr/include/tumbler-1/tumbler/tumbler-cache-plugin.h
/usr/include/tumbler-1/tumbler/tumbler-config.h
/usr/include/tumbler-1/tumbler/tumbler-enum-types.h
/usr/include/tumbler-1/tumbler/tumbler-error.h
/usr/include/tumbler-1/tumbler/tumbler-file-info.h
/usr/include/tumbler-1/tumbler/tumbler-glib-extensions.h
/usr/include/tumbler-1/tumbler/tumbler-marshal.h
/usr/include/tumbler-1/tumbler/tumbler-provider-factory.h
/usr/include/tumbler-1/tumbler/tumbler-provider-plugin.h
/usr/include/tumbler-1/tumbler/tumbler-thumbnailer-provider.h
/usr/include/tumbler-1/tumbler/tumbler-thumbnailer.h
/usr/include/tumbler-1/tumbler/tumbler-thumbnail.h
/usr/include/tumbler-1/tumbler/tumbler-thumbnail-flavor.h
/usr/include/tumbler-1/tumbler/tumbler-util.h