Eclipse can't run java project with module warning

I'm running eclipse 4.16 with OpenJDK-14. I have a simple java project that has a lib folder with swt.jar in it. It was added to the modulepath in the project's Properties > Java build path > Libraries dialog. When I import and use an swt class in my class, I'm prompted to add an entry to my module-info file. It adds "swt" with a warning:

Name of automatic module 'swt' is unstable, it is derived from the module's file name.

When I try to run the project as a java application I get this error in console and nothing runs:

Error occurred during initialization of boot layer
java.lang.module.FindException: Module swt not found, required by ca.footeware.swt.converter

If I export the project as a runnable jar with dependencies enclosed, it works with a similar warning. The exported jar does run (but it's not a convenient development cycle

I read somewhere that for non-modular jars a MANIFEST.MF header, Automatic-Module-Name, can be used. I cracked open the swt.jar and added the header with value org.eclipse.swt, the root package of the jar. I removed the Requires swt; from my module-info.java and again was prompted to add an entry from my class with an swt import. This time though it entered Requires org.eclipse.swt; and no warning was produced. When I tried running the project however I got the same error:

Error occurred during initialization of boot layer
java.lang.module.FindException: Module org.eclipse.swt not found, required by ca.footeware.swt.converter

I got it working! My Run Configuration's VM args is now:

--module-path ca.footeware.converter:ca.footeware.converter.temperature:/home/craig/Downloads/swt.jar -m ca.footeware.converter/ca.footeware.converter.Converter

I'm on linux and the --module-path separator should be :, not ;.

Note I've set the Run Configuration's Working Directory to ${workspace_loc} rather than the default ${workspace_loc:ca.footeware.converter} so that I could access both module projects by simple name rather than fully qualified name, e.g. /home/craig/workspace/ca.footeware.converter.temperature.