Warning popups do not copy to clipboard, can't easily google

I'm trying out the new tidy/lazy support in 4.6. A few of the messages spark my curiosity, so I'd like to learn more about them. I hover over the triangle, get the popup, I can select the text (though in gray background) I hit copy (command c in OSX) and the popup disappears. he text is not in the clipboard.

It would be cool if I could copy it. It would be even better if I could click on it and get to a page describing the warning/error.

For example: "-Wc++17-extensions" should take me to:
https://clang.llvm.org/docs/DiagnosticsReference.html#wc-17-extensions

I can't get a screenshot because the popup goes away on any keypress. (Which is probably why I can't copy it)