Comment 11 for bug 1756840

@Seth-Arnold I don't think your comment is relevant to the problem. Let expand on @savvdm Dmitry's comment, for I feel that a couple of balls were dropped, too.

Some of us have caught the habit of using a separate /home partition from the early days for the convenience of data-, settings-, and project retention. We have learned - and do so for years - that we can do a fresh install of a Ubuntu, and re-use the /home partition. When /home encryption was introduced, all we needed to do on a fresh install is use the same password, and things would be fine.

Now, without a clear warning, without a working alternative, and without an automatic conversion option, doing what we always did results in a broken/unusuable/reset home.

There's some mention of some deprecation in the release notes for the people who read those, "but surely the installer will take care of the necessary steps involved in transcoding this once promoted and defaulted feature, no?" (Spoiler: No, it does not.)

It should indeed be mentioned clearly in release notes (and in the installer imo) that you can't even log into your encryptfs-encrypted home with Ubuntu 18.04. Otherwise you'd expect something like this in the installer:

"We've detected an unsupported home encryption for user foobar. Would you like to:"

* Remove your prevous home (this will remove all your files);
* Leave your old files in the `.ecryptfs directory` for recovery purposes;
* Decrypt your previous home (all multiboot distros can use this user);
* Pick a different username (other multiboot distros can keep using this user);