RE: Regression in syslog-ng with libglib2.0_0 f2.84.0-1 // GLib:ERROR:../glib/gmain.c:4292:g_main_context_check_unlocked: assertion failed: (i <= 0 || fds[i - 1].fd < fds[i].fd) [libglib2.0_0 2.88.3-1, syslog-ng 3.2.5-3

Wow, okay, this is strange:

C:\> syslog-ng -F
{ fails with the libglib2.0_0 error }

C:\> syslog-ng -d
{ fails with the libglib2.0_0 error }

C:\> syslog-ng
{ runs in the background and stays running, but does not record anything to /var/log/messages }

So, two things;
1. forgetting foreground and debug (though, without at least debug, I wonder how to achieve this?), how to figure out why syslog() packets from a MikroTik host, on UDP, port 514, which I see from a packet capture on the Windows host where syslog-ng is running (in the background) ARE arriving, are not getting written to the configured messages-... log file?
2. what's different when syslog-ng is run with either -F or -d, that could be triggering the libglib2.0_0 error?

thank you,
Jay

-----Original Message-----
From: Takashi Yano <[email protected]> 
Sent: Thursday, August 13, 2026 7:42 AM
To: [email protected]
Subject: Re: Regression in syslog-ng with libglib2.0_0 f2.84.0-1 // GLib:ERROR:../glib/gmain.c:4292:g_main_context_check_unlocked: assertion failed: (i <= 0 || fds[i - 1].fd < fds[i].fd) [libglib2.0_0 2.88.3-1, syslog-ng 3.2.5-3

On Thu, 13 Aug 2026 04:03:01 +0000
Jay Libove Alzina wrote:
> Back a bit over a year ago, Sam Edge reported the below.
> I've just added syslog-ng into a CygWin 64 installation on a Windows 11 Pro system on which I've otherwise run CygWin for years, but I'm getting a similar error, log output starting syslog-ng with -F (foreground) -d (debug), below.
> Two things:
> 
>   1.  the blocking problem,
> GLib:ERROR:../glib/gmain.c:4292:g_main_context_check_unlocked: 
> assertion failed: (i <= 0 || fds[i - 1].fd < fds[i].fd) Bail out! 
> GLib:ERROR:../glib/gmain.c:4292:g_main_context_check_unlocked: 
> assertion failed: (i <= 0 || fds[i - 1].fd < fds[i].fd)
> 
> $ cygcheck -c|grep libglib
> libglib2.0_0                           2.88.3-1                 OK
> 
> # so, this is a much newer libglib2 than the one with which Sam 
> reported the error, so much newer that I'm very hesitant (expecting 
> dependency impossibilities) to even try load the older 2.64.6-1 which 
> Sam found to work; and anyway, this much newer, I'd have 
> expected/hoped the problem to have been fixed...)
> 
> 
>   1.  The several "Attempted to register the same plugin multiple times, ignoring" errors.
> This configuration was just installed; the config file created by syslog-ng-config, and edited only to add my network source, and a specific /var/log/messages-mycustomname destination:
> 
> The config file:
> 
> ######################################################################
> ####### # Based on the Default syslog-ng.conf file which would collect 
> all local logs into a # single file called /var/log/messages.
> # Added (enabled) UDP 514 network listening.
> # Added destination as /var/log/messages-MikroTiks for syslog() messages from my MikroTik routers.
> #
> 
> @version: 3.2
> @include "scl.conf"
> 
> source s_local {
>         system();
>         internal();
> };
> 
> 
> source s_network {
>         udp();
> };
> 
> destination d_local {
>         file("/var/log/messages");
> };
> 
> destination d_TikLogs {
>         file("/var/log/messages-MikroTiks");
> };
> 
> 
> log {
>         source(s_network);
>         destination(d_TikLogs);
> };
> 
> 
> log {
>         # We do not expect any locally generated syslog() messages, but ... ?
>         source(s_local);
>         destination(d_local);
> };
> 

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