Recurring Bun crash on Windows: panic(main thread): switch on corrupt value

[Infinitegameworks]

Environment

• Claude Code version: 2.1.45
• Bun: Canary v1.3.10-canary.63 (1979c945)
• OS: Windows 11 Pro 10.0.26100 (win11_dt)
• CPU: x64 (baseline) — sse42 avx avx2
• Machine RAM: 16.44GB

Crash Details

panic(main thread): switch on corrupt value

RSS: 0.62GB | Peak: 0.67GB | Commit: 0.92GB | Faults: 232217
Elapsed: 29596ms | User: 4343ms | Sys: 1203ms
Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) fetch(29) jsc spawn(16) standalone_executable process_dlopen yaml_parse(88)

Bun crash report link: https://bun.report/1.3.10/e_21979c94mgkgEugogC09gkQ4p4vbq705Vwws1U23wN284hUm5nlOiq4kOwkzjwDCYKERNEL32.DLLut0LCSntdll.dll4gijBA0eNorLs8sSc5QyM9TSM4vKiotKFEoS8wpTQUAa8EI/A

Behavior

• Crash occurs randomly — no consistent trigger identified
• Has happened multiple times across different sessions
• No specific operation (multi-agent, file reads, etc.) consistently reproduces it
• The switch on corrupt value panic suggests a GC race or memory corruption in Bun's JSC backend on Windows

Expected Behavior

Claude Code should not crash with a Bun runtime panic during normal usage.

Additional Context

Installed via npm (@anthropic-ai/claude-code). Running as standalone executable at C:\Users\bluey\.local\bin\claude.exe.

[github-actions]

Found 1 possible duplicate issue:

1. [BUG] [Windows] Bun panic "switch on corrupt value" crashes during Bash tool execution (v2.1.45 / Bun 1.3.10-canary.63) #26531

This issue will be automatically closed as a duplicate in 3 days.

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🤖 Generated with Claude Code

[liamavtal]

Also experiencing this on Windows 11 Home 10.0.26200, Claude Code 2.1.49.

Bun v1.3.10 (1423d3c8) Windows x64 (baseline)
Elapsed: 55961248ms (~15.5 hours) | User: 495843ms | Sys: 161359ms
RSS: 0.49GB | Peak: 1.15GB | Commit: 2.17GB | Faults: 2804401 | Machine: 34.16GB

panic(main thread): switch on corrupt value

Crash happened after an extended session. This is a recurring issue — happens frequently on long sessions. Please prioritize a fix for the bundled Bun runtime on Windows.

[Renaissance868]

Adding another data point for this crash:

• Claude Code version: 2.1.51
• Bun: v1.3.10 (1423d3c8) — stable release, not canary
• OS: Windows 11 Pro 10.0.26100 (x64, sse4.2 avx avx2)
• Machine RAM: 34.25GB
• Concurrent local agents: 3
• Session duration: ~10,869,681ms (~3 hours)
• Memory at crash: RSS: 0.86GB | Peak: 1.59GB | Commit: 3.27GB | Faults: 14,419,599
• Features: fetch(10929) jsc spawn(168) yaml_parse(571)

This case involved significantly longer runtime and higher memory usage (3.27GB committed vs 0.92GB) with 3 concurrent agents, suggesting the corruption may be exacerbated by sustained multi-agent workloads on Windows.

[github-actions]

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.