There’s a command line built into Firefox, which allows various options such as taking screenshots and restarting the browser. It used to open with Shift+F2, but since the upgrade to Firefox 57, that no longer does anything.
I have seen the command line since the upgrade (it was open in one Firefox window, and remained open after the upgrade), so I know that it does still exist in Firefox Quantum. However, I have since closed that window, and cannot get it back. Is there now a different keyboard shortcut to reveal the command line?
The Mozilla documentation for the command line still says Shift+F2.
I am using Firefox Quantum 57.0 on Ubuntu 17.10.