glxinfo not working - cannot find symbol pthread_create

[UniversE47]

I wanted to debug rendering problems that occurred in an SDL2 + OpenGL application.

So I tried to install mesa-demos to run glxinfo and glxgears.

But all demo programs that I've tried terminate with the following error message

Unable to find symbol pthread_create. Aborting.

Indeed, the binaries are not linked against libpthread, and while the libc contains various pthread symbols, it does not contain pthread_create.

Installation is almost fresh 23.06.05 based on 13.2-STABLE GENERIC amd64 and unmodified. Only installed some software that should be irrelevant for this problem, and the linux_base-c7-7.9.2009_1 package, that might be somehow relevant, but without that, the JetBrains CLion IDE does not work properly.

nvidia-driver-525.116.03 was already installed after installing from live media.

Also installed by default: mesa-dri-22.3.7_2 and mesa-libs-22.3.7_1


This should be the relevant part from /etc/rc.conf, default and unmodified after installation.

kld_list="linux linux64 cuse fusefs"
kldload_nvidia="nvidia-modeset"


Does anyone have an idea what might be going wrong?

Thank you for your help!