PHP 8.5 FPM access log lines also go to STDERR

[rainerjung]

Description

We tested PHP 8.5 and noticed a change between alpha2 and beta2, which still exists in RC1: all lines going to a configured access log file in FPM also seems to get send to Apache as errors, so probably they are somehow also written to STDERR.

Example:

• custom FPM access log line:

::1 -  29/Sep/2025:11:52:53 +0200 "GET /status?json&full" 200 - 0.710 2048 0.00%

• unexpected line in Apache httpd error log file:

:1 -  29/Sep/2025:11:52:53 +0200 "GET /status?json&full" 200 - 0.710 2048 0.00%', referer http://myserver/status.html

Looking at FPM changes, this is likely due to the fix for issue #12302 in PR #18725 (Commit cfb3e98).

PHP Version

PHP 8.5.0RC1 (cli) (built: Sep 28 2025 09:40:27) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.5.0RC1, Copyright (c) Zend Technologies
    with Zend OPcache v8.5.0RC1, Copyright (c), by Zend Technologies

Operating System

Linux RHEL 9

[Victor-D]

Hello

We also detected the same issue in zlog_stream_init_internal() with PHP 8.5.0 RC1 on Debian systems running php-fpm with access logs direct writing (no syslog).

Access logs are written in the php-fpm access log file, but also in the stderr, resulting being written in the Apache error logs.

This is a blocker for production release because it will generate too much logs :(