dbus-broker falls back to nss with 4.13 kernel

[Mdyrl7777777]

I'm using latest stable kernel 4.13.4 which have SO_PEERGROUPS support but dbus-broker still warns about it:
dbus-broker-launch: Falling back to resolving auxillary groups using nss, this is racy and may cause deadlocks. Update to a kernel with SO_PEERGROUPS support.

Is there specific config option need to be enabled in kernel or is this false warning?

[Keruspe]

This is a build-time check, not a runtime one, so you need linux-headers >= 4.13 when building dbus-broker to effectively use the SO_PEERGROUPS stuff.

[Mdyrl7777777]

I didn't know that linux-headers is build-time dependency. I think it isn't listed as dependency in any distro that have dbus-broker packages https://github.com/bus1/dbus-broker/wiki#available-packages

[Mdyrl7777777]

Sorry, maybe I misunderstand this. In Archlinux there are two headers packages:
https://www.archlinux.org/packages/core/any/linux-api-headers/ for userspace
https://www.archlinux.org/packages/core/x86_64/linux-headers/ for kernel modules
The former is currently at 4.12.7 version. I guess that's the reason why SO_PEERGROUPS isn't supported, right?

[Keruspe]

Whichever provides asm-generic/socket.h needs to be at least version 4.13

[dvdhrm]

It's linux-api-headers on arch-linux. Unfortunately, they haven't updated it to 4.13, yet.

[Mdyrl7777777]

Updating linux-api-headers to 4.13 solved this. Thx for help.