Not sure. One of the issues with OpenWrt’s build system is that in a bunch of situations it relies on the system python, and often the system python is in a strange state. To avoid debugging Python issues, you could remove wireshark from the build, since it’s not important.
To do this, remove the wireshark_diffconfig symlink from whatever board you’re trying to build (e.g. rm boards/ekh01v2/wireshark_diffconfig) and run morse_setup.sh -b ekh01v2, then rerun make.