Comment 9 for bug 1005372

I can't backport conky-all 1.9.0-2 due to a problematic build dependency:
Package libxnvctrl-dev is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
However the following packages replace it:
  nvidia-settings-updates:i386 nvidia-settings:i386 nvidia-settings-updates
  nvidia-settings

E: Package 'libxnvctrl-dev' has no installation candidate

It seems this package is no longer virtual in trusty-backports and later.