Sidebar size in DevTools

Surprisingly, SideBarPanel is not the full height of the container by default. I can't figure out how to make it 100% height. This is what it looks like now.

Note that this is slightly less than half the height of the sidebar container. Other panels do not have this problem. I tried to set the html and body of the panel to 100% via CSS and I tried to call

sidebar.setHeight('100%');

both before and after sidebar.setPage

. Instead of doing something, it doesn't render anything (possibly because it doesn't support% height from this method). I don't know how to debug the JS or CSS of the devtools extensions, so I'm not sure how to determine what is going on. I know the error can be viewed from the Chrome extension Devtools, but in this case, no error occurs.

As a bonus question, showing me how to debug devtools extensions would be nice. (Googling is not possible, as you just get normal debugging guides.)