Bash tool drops all stdout on Windows/Git Bash intermittently

Summary

On Windows 11 with Git Bash as the Bash tool shell, commands intermittently return (Bash completed with no output) even though they clearly ran. The same commands executed via the PowerShell tool in the same session produce output normally.

Repro

Run via the Bash tool on Windows:

echo "test"; whoami; pwd

Sometimes returns (Bash completed with no output) — verified 2026-07-03 in session dbb3ea90-5e90-4bb8-b314-25776b52f0d1, where an entire chain of commands returned nothing while the PowerShell tool in the same session worked fine.

Impact

This blocks SSH usage from the Bash tool — output from ssh user@host '...' is silently dropped, so any remote command result is invisible. Workaround has been to route all SSH through PowerShell instead, which is tracked as a persistent instruction in our setup.

Environment

• Claude Code on Windows 11 (build 10.0.22000)
• Shell: Git Bash (POSIX sh)

Questions

• Is this a harness-side stdout capture bug, or a Git Bash / MSYS PTY interaction?
• Would enabling a PTY flag (or forcing line-buffered capture) resolve it, or does this need a harness fix?