/usr/include/libsoup-2.4/libsoup/ is in libsoup2.4-dev 2.44.2-1ubuntu2.3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libsoup-2.4/libsoup/soup-address.h
/usr/include/libsoup-2.4/libsoup/soup-auth-domain-basic.h
/usr/include/libsoup-2.4/libsoup/soup-auth-domain-digest.h
/usr/include/libsoup-2.4/libsoup/soup-auth-domain.h
/usr/include/libsoup-2.4/libsoup/soup-auth-manager.h
/usr/include/libsoup-2.4/libsoup/soup-auth.h
/usr/include/libsoup-2.4/libsoup/soup-cache.h
/usr/include/libsoup-2.4/libsoup/soup-content-decoder.h
/usr/include/libsoup-2.4/libsoup/soup-content-sniffer.h
/usr/include/libsoup-2.4/libsoup/soup-cookie-jar-db.h
/usr/include/libsoup-2.4/libsoup/soup-cookie-jar-text.h
/usr/include/libsoup-2.4/libsoup/soup-cookie-jar.h
/usr/include/libsoup-2.4/libsoup/soup-cookie.h
/usr/include/libsoup-2.4/libsoup/soup-date.h
/usr/include/libsoup-2.4/libsoup/soup-enum-types.h
/usr/include/libsoup-2.4/libsoup/soup-form.h
/usr/include/libsoup-2.4/libsoup/soup-headers.h
/usr/include/libsoup-2.4/libsoup/soup-logger.h
/usr/include/libsoup-2.4/libsoup/soup-message-body.h
/usr/include/libsoup-2.4/libsoup/soup-message-headers.h
/usr/include/libsoup-2.4/libsoup/soup-message.h
/usr/include/libsoup-2.4/libsoup/soup-method.h
/usr/include/libsoup-2.4/libsoup/soup-misc.h
/usr/include/libsoup-2.4/libsoup/soup-multipart-input-stream.h
/usr/include/libsoup-2.4/libsoup/soup-multipart.h
/usr/include/libsoup-2.4/libsoup/soup-password-manager.h
/usr/include/libsoup-2.4/libsoup/soup-portability.h
/usr/include/libsoup-2.4/libsoup/soup-proxy-resolver-default.h
/usr/include/libsoup-2.4/libsoup/soup-proxy-resolver.h
/usr/include/libsoup-2.4/libsoup/soup-proxy-uri-resolver.h
/usr/include/libsoup-2.4/libsoup/soup-request-data.h
/usr/include/libsoup-2.4/libsoup/soup-request-file.h
/usr/include/libsoup-2.4/libsoup/soup-request-http.h
/usr/include/libsoup-2.4/libsoup/soup-request.h
/usr/include/libsoup-2.4/libsoup/soup-requester.h
/usr/include/libsoup-2.4/libsoup/soup-server.h
/usr/include/libsoup-2.4/libsoup/soup-session-async.h
/usr/include/libsoup-2.4/libsoup/soup-session-feature.h
/usr/include/libsoup-2.4/libsoup/soup-session-sync.h
/usr/include/libsoup-2.4/libsoup/soup-session.h
/usr/include/libsoup-2.4/libsoup/soup-socket.h
/usr/include/libsoup-2.4/libsoup/soup-status.h
/usr/include/libsoup-2.4/libsoup/soup-tld.h
/usr/include/libsoup-2.4/libsoup/soup-types.h
/usr/include/libsoup-2.4/libsoup/soup-uri.h
/usr/include/libsoup-2.4/libsoup/soup-value-utils.h
/usr/include/libsoup-2.4/libsoup/soup-version.h
/usr/include/libsoup-2.4/libsoup/soup-xmlrpc.h
/usr/include/libsoup-2.4/libsoup/soup.h