This was fixed in the upload of update-manager 1:0.156.12:
update-manager (1:0.156.12) precise; urgency=low
[...]
[ Michael Vogt ]
[...]
* remove skype from the removal blacklist
update-manager will now be able to complete the upgrade, even if skype must be removed in the process. The skype package can be reinstalled immediately after upgrade.
This was fixed in the upload of update-manager 1:0.156.12:
update-manager (1:0.156.12) precise; urgency=low
[...]
[ Michael Vogt ]
[...]
* remove skype from the removal blacklist
update-manager will now be able to complete the upgrade, even if skype must be removed in the process. The skype package can be reinstalled immediately after upgrade.