This recently failed because the cuda package exceeded the max. body size.
I suppose it makes generally sense to be able to exclude packages as I
don't need that package anyways.
Usually this doesn't make sense because we want to build all packages which
were determined in the previous prepare action. When specifying the
packages again in the conduct build action we'd skip packages which are
pulled into the build as dependencies which is normally not desired.
Simply adding `--sign` to the `makepkg` flags doesn't work because it would
require setting up GPG within the chroot environment (of `makechrootpkg`).
When debugging it is anyways annoying that `makepkg` sends the `gpg` output
to `/dev/null`. This way the logs are preserved.
Martchus