I have created a PetaLinux project with external Linux sources specified.
When I run "petalinux-config -c kernel" to configure the kernel, I receive an error pointing to a log file for further information.
The log file indicates that a script called "merge_config.sh" was missing and as a result could not be called.
If this message consistently appears, you will need to add the following in <petalinux-project>/project-spec/meta-user/recipes-kernel/linux/linux-xlnx_%.bbappend:
DEPENDS += "kern-tools-native"