#43074 [Crash] Segmentation fault at address 0x0 on Windows x64 (ntdll.dll) with malformed bun.report URL

What version of Bun is running?

1.4.3 (8c28b3167)

What platform is your computer?

Microsoft Windows 11 Pro (Windows v10.26200), x64

What steps can reproduce the bug?

Executing Claude Code CLI (claude.exe v2.1.271 bundled standalone executable) with: --output-format stream-json --verbose --input-format stream-json --effort max --model claude-sonnet-5 --permission-prompt-tool std

What is the expected behavior?

The Bun panic handler should encode the crash payload, symbols, and system telemetry into a valid base64- or hash-encoded identifier within the URL path (e.g., https://bun.report/1.4.3/<encoded_crash_hash>). Navigating to this URL should redirect to a pre-filled GitHub issue template on oven-sh/bun with the stack trace, system architecture, and minidump metadata populated automatically.

What do you see instead?

Malformed Crash URL: The URL generator inserted a literal string and an unparsed module token into the path:

https://bun.report/1.4.3/.DLLu4mLCSntdll.dll4ulrBA2AA

Additional information

Claude Code process exited with code 3. stderr: ============================================================ Bun v1.4.3 (8c28b3167) Windows x64 Windows v10.26200 CPU: sse42 popcnt avx avx2 Args: "\AppData\Roaming\Claude\claude-code\2.1.271\claude.exe" "--output-format" "stream-json" "--verbose" "--input-format" "stream-json" "--effort" "max" "--model" "claude-sonnet-5" "--permission-prompt-tool" "std"... Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) fetch(2) jsc spawn(21) standalone_executable yaml_parse(23) claude_code Builtins: "bun:ffi" "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:constants" "node:crypto" "node:dns" "node:dns/promises" "node:events" "node:fs" "node:fs/promises" "node:http" "node:http2" "node:https" "node:module" "node:net" "node:os" "node:path" "node:path/posix" "node:path/win32" "node:perf_hooks" "node:process" "node:readline" "node:stream" "node:stream/consumers" "node:stream/promises" "node:string_decoder" "node:timers/promises" "node:tls" "node:tty" "node:url" "node:util" "node:util/types" "node:vm" "node:zlib" "ws"

panic(thread 43960): Segmentation fault at address 0x0 oh no: Bun has crashed. This indicates a bug in Bun, not your code.

To send a redacted crash report to Bun's team, please file a GitHub issue using the link below:

https://bun.report/1.4.3/.DLLu4mLCSntdll.dll4ulrBA2AA

============================================================ Bun v1.4.3 (8c28b3167) Windows x64 Windows v10.26200 CPU: sse42 popcnt avx avx2 Args: "\AppData\Roaming\Claude\claude-code\2.1.271\claude.exe" "--output-format" "stream-json" "--verbose" "--input-format" "stream-json" "--effort" "max" "--model" "claude-sonnet-5" "--permission-prompt-tool" "std"... Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) fetch(2) jsc spawn(21) standalone_executable yaml_parse(23) claude_code Builtins: "bun:ffi" "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:constants" "node:crypto" "node:dns" "node:dns/promises" "node:events" "node:fs" "node:fs/promises" "node:http" "node:http2" "node:https" "node:module" "node:net" "node:os" "node:path" "node:path/posix" "node:path/win32" "node:perf_hooks" "node:process" "node:readline" "node:stream" "node:stream/consumers" "node:stream/promises" "node:string_decoder" "node:timers/promises" "node:tls" "node:tty Elapsed: 2997ms | User: 1125ms | Sys: 453ms RSS: 0.28 GB | Peak: 0.51 GB | Commit: 0.44 GB | Faults: 140505 | Machine: 68.63 GB panic(thread 43960): Segmentation fault at address 0x0 oh no: Bun has crashed. This indicates a bug in Bun, not your code. To send a redacted crash report to Bun's team, please file a GitHub issue using the link below: https://bun.report/1.4.3/.DLLu4mLCSntdll.dll4ulrBA2AA