bug#54770: Non-root LUKS devices unusable after Shepherd upgrade

[Christoph Weiss]

I ran into the same issue (no prompt but instead about 32 times the 
message "Nothing to read on input.")

I bisected this issue myself (starting before the fix was pushed) and 
arrived at 400c9ed3d779308e56038305d40cd93acb496180 as the culprit.

However, even with the current master 
(aa5716703fd4603dd89ce9b55f555b7aa85f4c9b), the issue has not been fixed 
for me.

Please let me know if I should provide any specific info.

Thank you.