You can uninstall or removes an installed libghc-darcs-dev-2.8.5-2a254 package itself from Debian 8 (Jessie) through the terminal,
$ sudo apt-get remove libghc-darcs-dev-2.8.5-2a254
If you would like to remove libghc-darcs-dev-2.8.5-2a254 and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove libghc-darcs-dev-2.8.5-2a254
If you use with purge options to libghc-darcs-dev-2.8.5-2a254 package all the configuration and dependent packages will be removed.
$ sudo apt-get purge libghc-darcs-dev-2.8.5-2a254
If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.
$ sudo apt-get purge --auto-remove libghc-darcs-dev-2.8.5-2a254