Spinner characters have inconsistent widths in Noto Sans Mono

Description

The thinking spinner causes visible horizontal jumping/jittering in COSMIC Terminal (System76's Wayland compositor) with Noto Sans Mono, which is the default monospace font on Fedora.

Root Cause

The non-Ghostty spinner frames use characters with inconsistent rendered widths in Noto Sans Mono:

· ✢ * ✶ ✻ ✽
(U+00B7, U+2722, U+002A, U+2736, U+273B, U+273D)

These cycle forward and reverse, and because some characters are wider or narrower than others in the font, the text after the spinner shifts horizontally on each frame change.

There's already a Ghostty-specific workaround (different frame set when $TERM is xterm-ghostty), which suggests this class of issue is known.

Workaround

Setting prefersReducedMotion: true in ~/.claude/settings.json fixes it by using a single ● character instead.

Environment

• Terminal: COSMIC Terminal 1.0 (cosmic-term)
• $TERM: xterm-256color
• Font: Noto Sans Mono (default monospace on Fedora 43)
• OS: Fedora 43 (COSMIC variant)
• Claude Code: 2.1.87

Suggestion

Consider either:

1. Adding a COSMIC Terminal detection path (though $TERM is generic xterm-256color)
2. Using spinner characters that are consistently single-cell width across common monospace fonts — this is probably the most robust fix since the issue could affect any terminal with Noto Sans Mono

🤖 Generated with Claude Code