emoji width bugs mostly come down to how terminals interpret Unicode's "grapheme clusters" vs "codepoints" vs "display cells". emoji isn't one codepoint - it's often multiple joined by zero-width joiners, variation selectors, skin tone modifiers. so the terminal asks wcwidth(), gets 1 or 2, but the actual glyph might render wider or combine into a single shape.

some emoji even change width depending on font. family emoji is like 7 codepoints, shows up as one glyph. most terminals don't track that. they just count codepoints and pray.

unless terminal is using a grapheme-aware renderer and syncs with the font's shaping engine (like freetype or coretext), it'll always guess wrong. wezterm and kitty kinda parse it right often

I'd be happy if we could get terminals to agree on how wide the warning triangle emoji renders. The emoji are certainly useful for scripts, but often widths are such a crapshoot. I cannot add width detection to every bash script I write for every emoji I want to use.

If only there was a standards body that could perhaps spec how these work in terminals.