Thanks Pat. My device isn’t Yocto, so that mapping doesn’t apply to me.
Internally, from the source code, the client defaults to using /var/lib/mender for the data directory. It’s up to the OS if that is actually a symlink or not.
However, the main issue here is that the -d option isn’t overriding that default in all cases and both directories are being written to, which I think might be a bug as it doesn’t make sense.