I'm using SFDX for development, and I've got a managed package in my packaging org. I need to tweak some things and don't want to increment the version... but I don't know how to deploy to a Patch Org. Can't find any docs on it...
You can convert your sfdx project into metadata format and then deploy to the patch org. Do something like,
sfdx force:source:convert -d mdapi
sfdx force:mdapi:deploy -d mdapi -u <patch org username> -w 1000