Bug#306976: debian-installer: monolithic should use libdevmapper1.01-udeb.
The file build/pkg-lists/monolithic/common still mentions
libdevmapper1.00-udeb which isn't available anymore and should
instead say libdevmapper1.01-udeb.
This is affecting building the package on amd64. It's the only
arch that builds the monolithic package.
Note that this has been fixed in svn trunk a long time ago, it
just didn't make it to the archive yet.