Undocked dev tool disappears.
Undocked dev tool window should be visible
Note: If the dev tool window still shows, try closing it and reopening a new one.
-Open the Cypress test launcher
-run a test (using Chrome 69)
-Open the chrome dev tools from the nested browser in cypress runner (... more tools- > developper tools)

Workaround:
Re dock the window using the shortcut keys (cmd+shift+D) to make it appear once more.
Cypress Version 3.1.0 (3.1.0)
Chrome 69
Mac 10.13.4
youps
looks like a dup of
https://github.com/cypress-io/cypress/issues/2497
Hi @Francis-Moreau-adsk, I'm closing this in favor of #2497
@Francis-Moreau-adsk thanks for the workaround! I just ran into this issue as well.
thanks!.. couldn't find a way to bring it back
Posting workaround from the question here to make it more prominent:
Workaround:
Re dock the window using the shortcut keys (cmd+shift+D) to make it appear once more.
Most helpful comment
Posting workaround from the question here to make it more prominent: