E build-depends-on-metapackage

Packages must not build-depend on metapackages.

Metapackages such as xorg, xorg-dev, x-window-system, x-window-system-dev and x-window-system-core exist only for the benefit of users and should not be used in package build dependencies.

Refer to https://wiki.debian.org/Lintian/Tags/depends-on-metapackage for details.