Graphical installer fails with encrypted volume

[arno]

Testet with Ubuntu (Mate) 19.10 and 20.04 beta - but I guess the graphical installer is same for all flavours.

I have a single harddrive with a windows installation (sda1..4) and want to install an encrypted linux beside Windows.

First I booted into installer from USB stick.
In manual partitioning I created
sda5 ext4 /boot
sda6 encrpyted volume, give password "aaa"
sda7 encrpyted volume, give password "aaa"
sda6_crypt: ext4 /
sda7_crypt: ext4 /opt

In the next step I will ask for username, devicename and password.
While that I get an error:

mount of ext4 to an encrypted volume as / fails

I would expect I can setup an encrypted Linux out of the graphical installer, so no need to use console commands...

Edit:

I found that it works with just one encrypted volume. But adding the second volume /opt seems to wipe out the /. At least this is what I see in the partion scheme if I go back when this error message occurs.

So this bug seems to be happen if more than one encrypted volume is used.

Question:

If it would be possible to allow 2 encrypted partitions and both have same key: Howto make it comfortable and type in just one key for both?

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

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[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[arno (star-gmx)]

Any news here? Is is worth to try a newer Ubuntu 21.04 maybe?