Debugging multi-release JARs can be a pain, because their corresponding sources generally do not include the multi-release overlays. I'd like to propose a convention for multi-release source JARs. AFAIK there is no specification for source JARs, but Maven and other build tools commonly output source JARs as a part of their build, hence the term "convention" instead of "standard".
The convention would be simple: the source JAR should include META-INF/versions directories exactly as specified in JEP 238. IDEs and other tooling should consider the running or configured project JDK version when determining which sources to examine or display to the user. I don't think the Multi-Release attribute should be required for source JARs. That attribute would be gleaned from the corresponding .class JAR; requiring it in the source JAR seems redundant. WDYT? -- - DML
