The LGPL is not a license of its own, but an extension of the GPL. It states:
This version of the GNU Lesser General Public License incorporates the terms and conditions of version 3 of the GNU General Public License, supplemented by the additional permissions listed below.
Since theThe LGPL license document only contains the extensions, so to provide the complete license you will also need to copy the vanilla GPL. It is reasonable to require a user of a LGPL library to provide the full license of the library they are using.