"Close except for these processes" does not work

Steps to reproduce:

• brew install zsh
• chsh /usr/local/bin/zsh
• Upgrade to latest iTerm beta (received prompt this morning)
• Edit preferences so "zsh" is among "Prompt before closing if there are jobs running besides..."
• Open a new tab running zsh
• Attempt to close the new tab

I expect the tab to close since there is nothing running in it besides zsh. Instead I get prompted that "zsh is running" do I still want to close the tab.

I switched back to the mainline iTerm channel so I can keep getting work done, hopefully there is enough info here to reproduce.