My lottery guess is that your error has something common with this error I experiense.
And that is, probably RTNETLINK that looks suspicious (not working).
So maybe we have an issue with RTNETLINK in the builds and @qosmio just another blind guess - can it be somehow connected with your recent DNS issue.
I first experienced that error once I changed some advanced configuration settings that I made looking here.
I changed the below settings. Before that I used only default settings and I didn't experienced that error.
CONFIG_USE_MOLD=y
CONFIG_USE_LTO=y
CONFIG_USE_GC_SECTIONS=y
CONFIG_TARGET_OPTIONS=y
CONFIG_TARGET_OPTIMIZATION="-O3 -pipe -mcpu=cortex-a53+crypto+crc"
# CONFIG_SECCOMP is not set
CONFIG_PKG_RELRO_PARTIAL=y
# CONFIG_PKG_RELRO_FULL is not set
# CONFIG_KERNEL_WERROR is not set
# CONFIG_KERNEL_SECCOMP is not set
# CONFIG_KERNEL_NAMESPACES is not set
# CONFIG_KERNEL_KEYS is not set
# CONFIG_KERNEL_IPV6_SEG6_LWTUNNEL is not set
# CONFIG_KERNEL_ELF_CORE is not set
# CONFIG_KERNEL_CGROUPS is not set
CONFIG_COLLECT_KERNEL_DEBUG=y
CONFIG_KERNEL_PERF_EVENTS=y
CONFIG_KERNEL_DYNAMIC_DEBUG=y
CONFIG_KERNEL_ARM_PMU=y
CONFIG_GCC_DEFAULT_PIE=y
CONFIG_EXPERIMENTAL=y
CONFIG_DEVEL=y
CONFIG_CCACHE=y
CONFIG_BUILD_PATENTED=y
And I've recently found out that if KERNEL_CGROUPS isn't used on ipq806x (R7800) the compiled firmware will not include cpuset and thus unable to use it in a script that sets different services to different cpu cores (irq affinity). Although there is a script that can set them without using cpuset.
Another error for example on ipq806x, messing with those advanced settings, was that zerotier started to spit segmentation fault error. This error appeared once I used GCC 13.1 (default for 23.05 is GCC 12.3) and CGROUPS enabled. Trial and error showed that zerotier works properly if I don't touch default advanced settings or I if use GCC 13.1 without CGROUPS. In latter case losing cpuset.
So obviously if any advanced setting is changed (better to not do it blindly) a good understanding of its functions is needed. But it's a good feeling to tackle with all these settings.
# CONFIG_KERNEL_CGROUPS is not set
I suspect that any of these advanced configuration settings might be the reason for these RTNETLINK errors. But its simply a guess based on what settings I changed in my config before and after that error appeared in my build.
Last but not least, there are many other settings in menuconfig that should be accounted for too.