Description

Tool output with multi-byte UTF-8 characters (emdash —, arrows →) shows up as � in the TUI.
The bash tool and prompt.ts both assemble child process stdout with output += chunk.toString(). When a multi-byte character gets split across two data events, chunk.toString() decodes each fragment independently and produces replacement characters.
Happens intermittently — depends on whether the OS splits the stdout delivery at a byte boundary that falls inside a multi-byte character.

Plugins

No response

OpenCode version

v1.2.15

Steps to reproduce

A command whose output contains emdash or arrow characters, viewed in the TUI. Easiest to reproduce with:

python3 -c "import os,time; os.write(1, b'cleanup \xe2'); time.sleep(0.05); os.write(1, b'\x80\x94 end')"

Screenshot and/or share link

No response

Operating System

Ubuntu 24.03

Terminal

kitty