[BUG] Bash/PowerShell tool execution broken mid-session — basic binaries missing (ssh, ls, which)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Partway through a long Claude Code session, both the Bash and PowerShell tools stopped working correctly:

Bash: even basic external binaries are missing — ssh: command not found, ls: command not found, which: command not found (only shell builtins like echo still work). This persisted across ~15+ separate attempts over more than 24 hours (last confirmed still broken 2026-09-06, first observed 2026-09-04 ~19:52).
PowerShell: every command fails outright with exit code 1 and no output at all, including a bare Write-Output "test".
Other tool categories (the in-app Browser tool, file read/write) continued working fine throughout — this looks isolated to the Bash/PowerShell execution sandbox specifically, not a session-wide failure.
Environment: Windows, Claude Code desktop app, working directory C:\AI-Workbench\Projects\voimar_eng.
Impact: Blocked all remote server administration (SSH-based deployment/verification work) for the remainder of the session — had to hand off remaining tasks as prompts for a fresh session instead.

Expected: Bash/PowerShell tools should either work normally or fail with a clear "sandbox unavailable" error rather than silently missing standard binaries.

What Should Happen?

Bash/PowerShell tools should either work normally or fail with a clear "sandbox unavailable" error rather than silently missing standard binaries.

Error Messages/Logs

My shell/SSH tooling is still down

Steps to Reproduce

Steps to Reproduce:

Start a long-running Claude Code session (this one was several hours in, spanning many prior tool calls including many successful Bash/SSH commands).
At some point partway through, Bash tool calls that had been working normally begin failing with <binary>: command not found for standard external binaries (ssh, ls, which) — only shell builtins like echo still work.
PowerShell tool calls fail outright (exit code 1, no output) from that point onward.
The failure is not tied to any specific command, argument, or user action — commands that had succeeded identically minutes earlier begin failing with no configuration change on either side.
Retrying the same commands repeatedly (15+ times over 24+ hours) produces the identical failure every time — no recovery observed within the session.
Not yet confirmed: whether starting a brand-new session resolves it (I'd recommend the reporter note whether that worked, since this may just be this session's sandbox specifically failing rather than a systemic bug).

Want me to fold that into the full report text I drafted earlier, or keep them separate so you can paste each into its own form field?

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

1.46

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_