I am following the steps outlined here to customize my Planck OLKB rev6 keyboard. I'm using QMK MSYS to perform all the command line level stuff.
I followed all the steps and everything works fine up until I need to compile the keyboard and a custom keymap using the qmk compile command. I keep getting an error:
Makefile:507: *** multiple target patterns. Stop.
The issue is also present when I try to compile the default Planck keymap. I'm really not sure what I'm doing wrong or if there any additional setup that is required.
I tried compiling using the JSON keymap file obtained from QMK configurator directly and that works (qmk compile [-c] <configuratorExport.json>).
For those struggling with compiling QMK locally, consider using Docker to compile it. You can run
util/docker_build.sh <keyboard>:<keymap>Docs: https://docs.qmk.fm/#/getting_started_docker
Of course this requires a local Docker installation, but that's arguably easier than installing all the build tools.