/usr/include/ is in libmongoc-dev 1.3.1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libmongoc-1.0/
/usr/include/libmongoc-1.0/mongoc-write-concern.h
/usr/include/libmongoc-1.0/mongoc-stream-file.h
/usr/include/libmongoc-1.0/mongoc-stream.h
/usr/include/libmongoc-1.0/op-header.def
/usr/include/libmongoc-1.0/mongoc-gridfs-file-page.h
/usr/include/libmongoc-1.0/op-query.def
/usr/include/libmongoc-1.0/mongoc-stream-tls.h
/usr/include/libmongoc-1.0/mongoc-version-functions.h
/usr/include/libmongoc-1.0/mongoc-stream-buffered.h
/usr/include/libmongoc-1.0/mongoc-read-concern.h
/usr/include/libmongoc-1.0/mongoc-bulk-operation.h
/usr/include/libmongoc-1.0/mongoc-iovec.h
/usr/include/libmongoc-1.0/mongoc-counters.defs
/usr/include/libmongoc-1.0/mongoc-init.h
/usr/include/libmongoc-1.0/mongoc-ssl.h
/usr/include/libmongoc-1.0/mongoc-stream-gridfs.h
/usr/include/libmongoc-1.0/op-reply.def
/usr/include/libmongoc-1.0/mongoc-find-and-modify.h
/usr/include/libmongoc-1.0/mongoc-gridfs.h
/usr/include/libmongoc-1.0/op-msg.def
/usr/include/libmongoc-1.0/mongoc.h
/usr/include/libmongoc-1.0/mongoc-uri.h
/usr/include/libmongoc-1.0/mongoc-opcode.h
/usr/include/libmongoc-1.0/mongoc-flags.h
/usr/include/libmongoc-1.0/mongoc-read-prefs.h
/usr/include/libmongoc-1.0/mongoc-host-list.h
/usr/include/libmongoc-1.0/mongoc-cursor.h
/usr/include/libmongoc-1.0/mongoc-error.h
/usr/include/libmongoc-1.0/mongoc-log.h
/usr/include/libmongoc-1.0/mongoc-database.h
/usr/include/libmongoc-1.0/op-get-more.def
/usr/include/libmongoc-1.0/mongoc-gridfs-file.h
/usr/include/libmongoc-1.0/op-delete.def
/usr/include/libmongoc-1.0/mongoc-matcher.h
/usr/include/libmongoc-1.0/op-update.def
/usr/include/libmongoc-1.0/mongoc-version.h
/usr/include/libmongoc-1.0/utlist.h
/usr/include/libmongoc-1.0/mongoc-index.h
/usr/include/libmongoc-1.0/op-insert.def
/usr/include/libmongoc-1.0/mongoc-config.h
/usr/include/libmongoc-1.0/mongoc-trace.h
/usr/include/libmongoc-1.0/mongoc-client-pool.h
/usr/include/libmongoc-1.0/mongoc-client.h
/usr/include/libmongoc-1.0/op-kill-cursors.def
/usr/include/libmongoc-1.0/mongoc-gridfs-file-list.h
/usr/include/libmongoc-1.0/mongoc-rand.h
/usr/include/libmongoc-1.0/mongoc-stream-socket.h
/usr/include/libmongoc-1.0/mongoc-server-description.h
/usr/include/libmongoc-1.0/mongoc-collection.h
/usr/include/libmongoc-1.0/mongoc-socket.h