git clone https://git.openwrt.org/openwrt/openwrt.git && cd openwrt
git checkout v19.07.8
wget -O .config https://downloads.openwrt.org/releases/19.07.8/targets/mvebu/cortexa9/config.buildinfo
make defconfig
make target/linux/compile
find build_dir/ -name .vermagic -exec cat {} \;
Based on .manifest file and checking 19.07.8 kernel version, the vermagic number should be a92a3f5c5bed2671533484c7ace9d5b5
This problem can also currently be observed inside 19.07.8 router's Software page when selecting package to install (kernel version dependency error message)