Thanks for taking your time to report this issue and help making Ubuntu better.
I was unable to reproduce this issue since I could install and run yakuake without issues on my Xenial vm. Did you get any error messages when attempting to install it intially? Since Xenial is the development version, packages are frequently updated so some of the dependencies might have been out of sync for a while, causing the package to be uninstallable. Do you still experience this problem?
Thanks for taking your time to report this issue and help making Ubuntu better.
I was unable to reproduce this issue since I could install and run yakuake without issues on my Xenial vm. Did you get any error messages when attempting to install it intially? Since Xenial is the development version, packages are frequently updated so some of the dependencies might have been out of sync for a while, causing the package to be uninstallable. Do you still experience this problem?