Alexander,
Thanks for your reply.
I've attached my new configure file that lives in: poky/meta-raspberrypi/conf/machine
Mea Culpa: I created this configure file and am using the MACHINE ??= "raspberrypi0-64-wf.conf" in my local.conf file.
Since the raspberrypi Zero support does not work out of the box. There is an issue in that it has to build as a 64 bit image or Raspberry Pi's boot loader won't load it. And then, the kernel modules are missing... and then the WIFI isn't installed completely and doesn't work anyways... etc... I created my own machine configuration file.
My current state has the image booting, I have a serial connection and through it I can try to bring up wifi by hand but the wpa-supplicant won't connect. My searches have found some information that it is a recent patch that has a side effect of not letting wpa-supplicant work with some raspberry Pi's. I gather an older version (2.9) does work so that's why I'm doing this.
I have no idea where the log file you referred to is or how to make bitbake generate it.
I did do a:
$ bitbake -c cleanall wpa-supplicant
I can see that the correct version is referenced.
Cheers!!