## Summary
This PR fixes infinite recursion and stack overflow crashes when error
objects have circular references in their properties, particularly when
`error.stack = error`.
### The Problem
When an error object's stack property references itself or creates a
circular reference chain, Bun would enter infinite recursion and crash.
Common patterns that triggered this:
```javascript
const error = new Error();
error.stack = error; // Crash!
console.log(error);
// Or circular cause chains:
error1.cause = error2;
error2.cause = error1; // Crash!
```
### The Solution
Added proper circular reference detection at three levels:
1. **C++ bindings layer** (`bindings.cpp`): Skip processing if `stack`
property equals the error object itself
2. **VirtualMachine layer** (`VirtualMachine.zig`): Track visited errors
when printing error instances and their causes
3. **ConsoleObject layer** (`ConsoleObject.zig`): Properly coordinate
visited map between formatters
Circular references are now safely detected and printed as `[Circular]`
instead of causing crashes.
## Test plan
Added comprehensive tests in
`test/regression/issue/circular-error-stack.test.ts`:
- ✅ `error.stack = error` circular reference
- ✅ Nested circular references via error properties
- ✅ Circular cause chains (`error1.cause = error2; error2.cause =
error1`)
All tests pass:
```
bun test circular-error-stack.test.ts
✓ error with circular stack reference should not cause infinite recursion
✓ error with nested circular references should not cause infinite recursion
✓ error with circular reference in cause chain
```
Manual testing:
```javascript
// Before: Stack overflow crash
// After: Prints error normally
const error = new Error("Test");
error.stack = error;
console.log(error); // error: Test
```
🤖 Generated with [Claude Code](https://claude.ai/code)
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
