valgrind can optionally indeed be used by the developer of the
package to run the testsuite in a special mode. The testsuite
isn't run at all during package build and doing that in valgrind
mode wouldn't be particularly appropriate anyway.
Via gstreamer-plugins-->cheese there's a dependency
on dirac from gnome-control-center, and it seems even more inappropriate
to delay building that one until valgrind built on any architecture.
Please forward to factory.

- Don't buildrequire valgrind-devel anywhere, it's unused.