Was a little surprised to learn that the warning sign is generally considered an Emoji; I guess I don't think of it that way. Was even more surprised to learn that there is no great definition for what constitutes an Emoji. The term doesn't seem to have much meaning in Unicode. The warning sign - U+26A0 - goes all the way back to Unicode version 4.0 and is in the BMP, whereas most Emoji are in the SMP.
Somewhat related fun fact, anyone can submit an emoji to the Unicode Consortium annually, submissions are actually open right now: https://unicode.org/emoji/proposals.html.
The definition is messy, but the list of Unicode emojis is defined. Starting points: https://www.unicode.org/reports/tr51/, https://unicode.org/emoji/charts/full-emoji-list.html
I'm not aware of any emoji fonts like Symbola which provide a monospace typeface, though. That would be a great option.
You can do it on macOS as well, but you have to disable SIP and modify/replace the files for the Apple Color Emoji font, because some widely used GUI libs are hardcoded to use it.
Idr the situation on Windows except that emoji glyphs are inherited from your other font choices, if your chosen font includes emoji. But on Linux it's generally easy to configure certain font substitutions only for some groups of characters, like emoji.
At least in the blog there are a two spaces after the emoji so it can freely draw past its boundaries rightwards without colliding with anything for a good bit; and nothing to its right is used assuming monospace alignment. So at worst you just get a half-emoji.
gitk broke! Can't parse emojis
I want emojis in my code. They are a superior form of communication (non-linear)
Then you will enjoy swift [1]!
[1] Emoji driven development: https://www.swiftbysundell.com/special/emoji-driven-developm...