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Though Ubuntu 14.04 has been officially released, update-manager -d says that the distribution will be upgraded to a development version, still in testing.
Why? How long will I have to wait to have the stable in the repos?
From the man page of update-manager, the -d option:
Check if upgrading to the latest devel release is possible
So you are already asking update-manager to try and upgrade to a development release. Remove the-d and it will work
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