TypeError: A.with is not a function — regression in 2.1.78 on Node.js 18

Bug Report: TypeError regression in Claude Code 2.1.78

Summary

Claude Code 2.1.78 introduced a TypeError: A.with is not a function that kills sessions mid-execution. Not present in 2.1.74-2.1.77. Discovered while running Terminal-Bench (89 coding tasks) on Modal containers.

Reproduction

Any Claude Code 2.1.78 session running in a containerized environment (Modal, Daytona) with Node.js 18.x. The error fires during result serialization after the agent has been working — tasks complete their logic but the session crashes before clean exit.

TypeError: A.with is not a function
    at l5z (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:6892:266)
    at p5z (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:6887:12301)
    at file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:6887:12002
    at Array.reduce (<anonymous>)
    at file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:6887:11988
    at Array.forEach (<anonymous>)
    at UD (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:6887:10654)
    at pZq (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:6612:9819)
    at async file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:6612:6557
    at async Sf8 (file:///usr/local/lib/node_modules/@anthropic-ai/claude-code/cli.js:944:2408)

Evidence

We run the same 89-task benchmark across versions. The only variable between runs is the Claude Code version installed via npm install -g @anthropic-ai/claude-code@<version>:

| Claude Code | Run | Tasks | Pass Rate | TypeErrors | Errors |
|------------|-----|-------|-----------|------------|--------|
| 2.1.74 | v10b | 18 | 78% | 0 | 0 |
| 2.1.75 | v12 | 18 | 56% | 0 | 0 |
| 2.1.75 | v13 | 18 | 44% | 0 | 0 |
| 2.1.77 | v14 | 21 | 38% | 0 | 0 |
| 2.1.78 | v15 | 17 | 41% | 5 (29%) | 0 |
| 2.1.74 (pinned) | v16 | 5* | 80% | 0 | 0 |

*v16 still running at time of writing

Likely Root Cause

Array.prototype.with() is an ES2023 method requiring Node.js 20+. The minified symbol A.with in the stack trace suggests new code in 2.1.78 uses Array.with() in a result serialization path (l5z → p5z → UD → pZq). Modal/Daytona containers ship Node.js 18.x by default.

The error only fires after task execution — the agent reads files, writes code, runs tests — then Claude Code crashes during output processing. This means:

• Tasks that complete before the crash can still pass verification
• Tasks interrupted mid-stream get error_during_execution with 0 useful output
• The crash is non-deterministic in timing but consistent in occurrence

Environment

• Install method: npm install -g @anthropic-ai/claude-code@latest
• Container OS: Ubuntu (Modal sandboxes)
• Node.js: 18.x (installed via apt-get install nodejs)
• Invocation: claude -p "..." --output-format stream-json --dangerously-skip-permissions
• Auth: OAuth token via CLAUDE_CODE_OAUTH_TOKEN env var

Workaround

Pin to 2.1.77 or earlier:

npm install -g @anthropic-ai/claude-code@2.1.77

Impact

This blocks any CI/container pipeline using @latest on Node.js 18 environments. The error is silent (exit code 0) and only visible in stream-json output, making it hard to diagnose without log inspection.