[BUG] Bun v1.4.0 segfault at 0xFFFFFFFFFFFFFFFF ~30 min into remote-bridged session - 'exited with code 3' (Windows 11 26200, CC 2.1.209)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

A Claude Code desktop session on Windows died about 30 minutes in (Elapsed: 1817103ms) with "Claude Code process exited with code 3". The bundled claude.exe (2.1.209, Bun v1.4.0 standalone, baseline build) panicked with:

panic(main thread): Segmentation fault at address 0xFFFFFFFFFFFFFFFF

This appears to be the same crash-address family as #28789 (0xFFFFFFFFFFFFFFFF on Windows during normal usage), which was auto-closed as stale — its lock message asks for a new issue referencing it, hence this report. It is distinct from the 0x3C startup-segfault family (#76915, #55219): this one occurs mid-session on an established process, not at startup.

Context that may narrow it down:

• The session was a remote-bridged session (started/driven via the desktop bridge; --permission-prompt-tool stdio --input-format stream-json --output-format stream-json, and the process was resuming a session per the truncated --resu… arg).
• Immediately before the crash dump, the bridge logged two warnings: [bridge] no session-anchored default-branch evidence — omitting requested branch 'main' from outcomes.branches; the remote session will work on a generated branch instead. (Possibly unrelated, but it was the last output before the panic.)
• Memory was modest at crash time (RSS 0.44 GB, peak 0.45 GB, commit 0.68 GB on a 34 GB machine), but page faults were high (264,601).

What Should Happen?

The session should keep running; a segfault in the bundled runtime should not take down the session with a bare "exited with code 3".

Error Messages/Logs

============================================================
Bun v1.4.0 (a505a2999) Windows x64 (baseline)
Windows v10.26200
CPU: sse42 avx avx2
Args: "<home>\AppData\Roaming\Claude\claude-code\2.1.209\claude.exe" "--output-format" "stream-json" "--verbose" "--input-format" "stream-json" "--effort" "high" "--model" "claude-fable-5" "--permission-prompt-tool" "stdio" "--resu"...
Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) abort_signal(397) fetch(481) jsc spawn(113) standalone_executable yaml_parse(18) claude_code
Elapsed: 1817103ms | User: 14593ms | Sys: 5359ms
RSS: 0.44 GB | Peak: 0.45 GB | Commit: 0.68 GB | Faults: 264601 | Machine: 34.10 GB
panic(main thread): Segmentation fault at address 0xFFFFFFFFFFFFFFFF
oh no: Bun has crashed. This indicates a bug in Bun, not your code.

Bun crash report link (as printed; middle segment shown redacted in the captured output):
https://bun.report/1.4.0/<blob>/lCqy8/lC4x4huCq+hi3C_A2DD

Environment

• Claude Code 2.1.209 (desktop-app provisioned, %APPDATA%\Claude\claude-code\2.1.209\claude.exe)
• Bun v1.4.0 (a505a2999), Windows x64 baseline build
• Windows 11 Pro, build 26200
• 34 GB RAM, CPU with AVX2 (baseline Bun build in use)

Related: #28789 (same address, auto-closed stale), #65754 / #62055 (closed exit-code-3 reports), #76915 (startup 0x3C family, distinct signature).