Dev mode hangs when debugging Gradle plugin execution due to debug port collision across parent/child Gradle processes.

[scottkurz]

A simple: gradle libertyDev -Dorg.gradle.debug=true will typically hang.

The reason is that the JVM debug args will be constructed as: ...,suspend=y,address=5005 for the process running DevTask.

However, the child Gradle launched via BuildLauncher in DevTask:runGradleTask() will likewise be configured with the same exact JVM args. Because the daemon running the parent task is in-use, a new JVM/daemon will be needed. So the parent Gradle execution DevTask will hang waiting for the child, while it waits for a debugger connection.

Maybe we'd need to loop in the findAvailablePort processing to make this work.

Tried w/ LGP v3.5.2 but I think any recent version with dev mode would have this issue.

[scottkurz]

From above I had in mind the org.gradle.debug.port property, however it seems relatively recent. I see it added in https://docs.gradle.org/7.4/userguide/troubleshooting.html, but not the 7.3 doc. I'd imagine we could construct the JVM args: e.g. -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5009 more manually ourselves in LGP code if we really wanted to.