This is mostly a note for myself, as I was ready to pull my hair out earlier.
Interface Builder can get in your way when you want to create a single-column
NSTableView where the column fills the entire width available.
Setting the column count to 1 doesn’t automatically resize it, and extending the column using its resize handle or by setting its width to the width of the view can cause a horizontal scrollbar to appear.
The solution is to resize the view itself — so that you eat into the space occupied by the single column, and then expand back to your desired width. It is incredibly stupid. Here’s a video:
There’s a Stack Overflow question where the accepted answer recommends this method. Handily I misread it — only realising what it was saying after I’d stumbled across the resizing trick myself (after trying many other things).
In related news, I’m almost done with the excellent Big Nerd Ranch Cocoa book after getting sidetracked for two months.