●○○○ — Not much; I'm just letting you know about it.
Steps causing the bug to occur:
Loving the beta so far guys ;) Feels so smooth ;) Thank you.
So this is not really a bug, but
Set the editor in "Hide Toolbar Labels" mode
The node library closing button is hidden too, so you cannot close it when docked
I wonder, what would be more work for the team, re-adding a node library close button in Hidden Labels mode, or add a secondary shortcut to hide the node library, I don't know, maybe something like alt-cmd-return to hide it (one step towards the sub-requests of Option to hide Node Library more easily