I was able to get this working.
% atlas-create-jira-plugin
- Fails (not found) because all commands do not have the execute bit set
% chmod +x /Applications/Atlassian/atlassian-plugin-sdk-8.2.7/bin/*
% atlas-create-jira-plugin
Cannot find /Applications/Atlassian/atlassian-plugin-sdk-8.2.7/apache-maven-3.5.4/bin/mvn
This file is needed to run this program
% chmod +x /Applications/Atlassian/atlassian-plugin-sdk-8.2.7/apache-maven-3.5.4/bin/*
Apparently, if you are not an admin user (which is wise not be) the SDK does not install properly (no execute bits) and you have to fix it by hand.
Step 10 from https://developer.atlassian.com/server/framework/atlassian-sdk/create-a-confluence-hello-world-macro/ says:
Monitor the window where confluence was run originally and confirm that QuickReload finished loading. You should see a confirmation message:
This does not show up
When trying to start with JAVA_HOME set to Java 8, it hangs on atlas-run. I removed Java 8 to fall back on the MacPorts installed OpenJDK11. I will be running with Java 11 even if the Confluence environment complains (at least it runs).
With that I was able to compile and install and use the standard Hello World macro plugin.