Comment 8 for bug 622737

Well, xdeb relies on dpkg-cross for the actual crossing, so I guess that's the right package to fix this in.

Note that this is an Ubuntu-specific issue, as the mesa package in Ubuntu diverges from the Debian one in the use of this subdirectory + ld.so.conf dpkg alternative. The trivial thing for dpkg-cross to do is to special-case the contents of /usr/lib/mesa and map them to /usr/<arch>/lib.