First, #123456 is not a bug, it's a bug report. And second, #123456 suffices, doesn't it? By hardcoding the "bug" in there, you make it impossible to start a sentence with a bug number, e.g.:
First, #123456 is not a bug, it's a bug report. And second, #123456 suffices, doesn't it? By hardcoding the "bug" in there, you make it impossible to start a sentence with a bug number, e.g.: