## Description All bash commands inside Claude Code fail with exit code 1 on Windows after updating to v2.1.45. The underlying error is: Bash itself works fine — it cannot write to the stdout pipe that Claude Code (Node.js) creates. Even hello fails. ## Reproduction - Update to Claude Code v2.1.45 on Windows with Git Bash - Run any bash command (e.g. hello, /c/CC_Projects/Original-Writing_LOCAL) - All fail silently with exit code 1 Running bash through PowerShell reveals the actual error:

v2.1.45: Bash broken on Windows - bad file descriptor on stdout pipe

Status Fixed / completed

Maintainer reply None cached

Workaround ✓ Mentioned in description ↑

Activity 12 comments · opened Feb 18, 2026 · closed Feb 19, 2026

Description

All bash commands inside Claude Code fail with exit code 1 on Windows after updating to v2.1.45. The underlying error is:

Bash itself works fine — it cannot write to the stdout pipe that Claude Code (Node.js) creates. Even hello fails.

Reproduction

Update to Claude Code v2.1.45 on Windows with Git Bash
Run any bash command (e.g. hello, /c/CC_Projects/Original-Writing_LOCAL)
All fail silently with exit code 1

Running bash through PowerShell reveals the actual error:
Windows PowerShell
Copyright (C) Microsoft Corporation. All rights reserved.

Install the latest PowerShell for new features and improvements! https://aka.ms/PSWindows

PS C:\CC_Projects\Original-Writing_LOCAL> hello

Bash can still write to files (just not stdout):
test

Version comparison

Confirmed across multiple sessions using conversation export transcripts:

| Date | CC Version | Bash |
|------|-----------|------|
| 13 Feb | v2.1.39 | Working |
| 14 Feb | v2.1.41 | Working |
| 17 Feb | v2.1.44 | Working (x3 sessions) |
| 18 Feb | v2.1.45 | Broken (x2 sessions) |

The break correlates with the v2.1.45 changelog entry: Improved memory usage for shell commands that produce large output — RSS no longer grows unboundedly with command output size

Workaround

Downgrade to v2.1.44:

changed 2 packages in 3s

1 package is looking for funding
run npm fund for details

Note: if you also have the native installer at , it auto-updates independently and will override the npm version. Rename it to prevent it taking priority.

Environment

Windows 11 Home 10.0.26200
Git for Windows 2.52.0 (MSYS2/Cygwin)
Node.js v24.12.0
Claude Code v2.1.44 (npm) — working
Claude Code v2.1.45 (native + npm) — broken

View original on GitHub ↗

12 Comments

github-actions[bot] · 6 months ago

Found 2 possible duplicate issues:

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texturalbeing · 6 months ago

Additional: Bun runtime crash in v2.1.45

In the same v2.1.45 session (native installer binary), the Bun runtime itself crashed while executing a git add command:

Bun Canary v1.3.10-canary.63 (1979c945) Windows x64 (baseline)
Windows v.win11_dt
CPU: sse42 avx avx2
Args: "C:\Users\cogni\.local\bin\claude.exe"

panic(main thread): switch on corrupt value
oh no: Bun has crashed. This indicates a bug in Bun, not your code.

This killed the session entirely. The native claude.exe at .local\bin is a Bun standalone executable, so v2.1.45 had instability beyond the stdout pipe issue — the runtime itself was crashing.

Screenshot available if helpful.

rweijnen · 6 months ago

Is there no basic testing done before a release is thrown into the wild? Not the first time very essential things break!

mwebber92 · 6 months ago

can confirm its the latest version, downgraded to .44 and it works

duzenko · 6 months ago

Is there no basic testing done before a release is thrown into the wild? Not the first time very essential things break!

No testing and no bug support either
I suppose in a few days they will ask for a screenshot or a PR or something

FWIW 1.45 is not stable in npm, so fix with

npm install -g @anthropic-ai/claude-code@stable

$ claude --version
2.1.37 (Claude Code)

privacyguy123 · 6 months ago

Literally unusable. Need fix ASAP.

Jarred-Sumner · 6 months ago

This issue was fixed in Claude Code v2.1.47. Please run claude update to get the latest version.

rweijnen · 6 months ago

Thanks @Jarred-Sumner

Great that that the bug has been squatted. I do still wonder how this gets passed release testing. Is there also a change in the tests run before release to prevent this in the future ?

duzenko · 6 months ago

More importantly, has a new test been added for this exactly?

texturalbeing · 6 months ago

Thank you @Jarred-Sumner !

ThatDragonOverThere · 6 months ago

Related: Bun v1.3.10 I/O Handling on Windows

Bad file descriptor errors are another facet of Bun's broken Windows I/O. Part of a broader crash family: 20+ issues, 90+ users — segfaults, "switch on corrupt value" panics, TUI escapes, pipe crashes. Root cause (N-API race condition) documented on #21875 with 27 memory dumps. Zero staff response in 30+ days.

github-actions[bot] · 5 months ago

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.