Link from : https://github.com/compiler-explorer/compiler-explorer/issues/3224
https://godbolt.org/z/Gab81o4M7
It is supposed to have a gcc dump window opened for a single compiler. The window is here, but no compiler is attached, and some "undefined" can be seen in title, which is not a good sign.
I'm probably guilty here, with this https://github.com/compiler-explorer/compiler-explorer/pull/4369 changeset.