I had used it when Brett first mentioned it, and yet, yesterday when I wanted to try something on Linux, I couldn’t find it – even though I knew it was in the upper right quadrant of the screen. Good job hiding it, GitHub! 
I didn’t know there was a “comma” shortcut – I only know about the “period” shortcut for PRs.
Hopefully that was a transient failure.
Nope. I can’t use the comma , key from a PR to open a codespace. It always goes to this screen:
Whereupon when I click the “create new codespace” button it gives me a generic Github 500 error. 
(It’s on Github to monitor their logs and understand their 500 errors)
What does work is using the code space thing from the Code menu on the main /python/cpython/ repository page. I assume the gh command exists within that already setup so gh pr checkout NNN would work. I just haven’t tried it as I’ve normally got infinitely faster machines at my disposal. The codespace looks like a very nice thing to have!
