Deployment Automation Manager + Jenkins + DDL files issue

I'm trying to create an automated deployment of a hello-world appian application and running into some trouble.

Here is the background:
- I'm using Jenkins as my build server
- My source code is in gitlab.  The repo itself is a lightly modified version of github.com/.../devops-quickstart
- My hello-world application (it was given to me) consists of an aplication .zip export, and a single .sql DDL file
- My jenkins job is configured to use the build's last successful commit hash as the version manager's buildPackage's startHash... and it uses the current commit as the endHash.


Here's whats happening:
- On my local machine, I use the version manager to push the application zip and the single DDL file into the repo
- Jenkins picks up the change
- In my case, this is the first time this build is running (the initial deploy of the application), so there is no last successful git commit hash.. so endHash isn't set
- Jenkins runs buildPackage and creates waht looks correct... a package containig my entire application and the .sql file
- Jenkins runs the import manager against that built package, and succeeds in deploying it to my target appian environment

Here's where the trouble starts:
- I go back to designer and make a minor update.
- I create a patch, and export it.
- I go back to my version-manager.properties, i point applicationPath to my exported patch.zip, and i set uuid to my application's UUID
- I run addContents to add my patch... note:  I'm not specifying any ddlPath, as I'm not wanting to change or update any ddl scripts
- Jenkins builds the package, it looks correct... it seems to match the diff correctly
- Jenkins goes to import the package and fails:
2019-05-20 14:50:25,708 - Status: Failed. Current step: Executing DDL Scripts. Log file URL: http://<myappian>:8080/suite/doc/4315.  Error message: java.nio.file.NoSuchFileException: <xxx>/appian/tomcat/apache-tomcat/temp/deployment-automation6074984514420595931/ddl_files/<ddl name>.SQL.


I'm not sure what to make of this error, but it seems that the import is expecting a .sql file... however, in my mind, and in the buildPackage output, the diff that we're wanting to import does not contain a DDL change...
So why does it seem to be expecting a sql file?

I think I might be misunderstanding the DDL capabilities of the deployment automation manager...  If anyone can help me understand this error or why it's happening, it'd be greatly appreciated.