[Bug]: [macOS 27 / Apple Silicon] Herd PHP-FPM crashes on every outbound DNS/HTTP request: SIGABRT “multi-threaded process forked” causes 502 across all PHP versions

### Platform

macOS

### Operating system version

macOS 27.0 (26A5388g), Apple Silicon

### System architecture

ARM64 (M1, M2, etc)

### Herd Version

Herd 1.29.0 (65)

### PHP Version

PHP versions 8.3, 8.4, and 8.5

### Bug description

The stack excerpt above

[php85-fpm-2026-07-28-100551.0004.txt](https://github.com/user-attachments/files/30465743/php85-fpm-2026-07-28-100551.0004.txt)

### Steps to reproduce

direct Herd FPM returns 502; php artisan serve works

### Relevant log output

```shell

```

Start with the attached php85-fpm stack excerpt and reproduce the 502 using direct Herd FPM on Apple Silicon with the listed PHP versions. Compare that behavior with php artisan serve and inspect the reported SIGABRT around outbound DNS/HTTP requests; done means identifying a reproducible cause and a validated fix or clear upstream diagnosis.

Written by the indexing model from the issue text.