RangeError: Maximum call stack size exceeded in message streaming

Bug Description

Claude Code crashes with a RangeError: Maximum call stack size exceeded error during normal operation. The error occurs in the CLI's message streaming/event handling code.

Error Message

file:///<user-home>/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:496
`);B.enqueue(Y)}catch(G){B.error(G)}},async cancel(){await Q.return?.()}})}}});var A01=w(()=>{He1()});function De1(A,Q){if(!Q||!("parse"in(Q.output_format??{})))return{...A,content:A.content.map((B)=>{if(B.type==="text")return{...B,parsed:null};return B}),parsed_output:null};return Fe1(A,Q)}...

RangeError: Maximum call stack size exceeded

Environment

• OS: macOS (Darwin 24.5.0)
• Platform: darwin

Steps to Reproduce

The crash occurred during normal Claude Code operation. The specific trigger is unclear, but it appears to happen during message streaming/response processing.

Expected Behavior

Claude Code should handle message streaming without stack overflow errors.

Actual Behavior

The CLI crashes with RangeError: Maximum call stack size exceeded, preventing completion of the operation.

Analysis

The error appears to originate in the _QA class which handles message streaming, event emission, and async iteration. The stack overflow suggests either:

1. Deeply nested recursive calls in the event handling chain
2. An infinite loop in message/event processing
3. Circular references in the streaming state machine

Additional Context

The affected code handles core functionality including:

• Message streaming (_fromReadableStream, _createMessage)
• Event emission (_emit, event listeners)
• Async iteration (Symbol.asyncIterator)
• Content block processing

This is a blocking issue that prevents normal CLI usage.