Skip CDS test if the JDK cannot create AppCDS

[dmlloyd]

This assumes that we are only testing the CDS works if it can be created. If it cannot be created because the JVM does not support it, we should not fail the entire build.

/cc @geoand just to make sure this makes sense.

[quarkus-bot]

✔️ The latest workflow run for the pull request has completed successfully.

It should be safe to merge provided you have a look at the other checks in the summary.

[geoand]

I'm interested in hearing about which JVM doesn't support AppCDS 😎

[dmlloyd]

Mine, apparently! 🤷‍♂️

[geoand]

Fair enough :)

[gsmet]

And we are sure we will NEVER have this message when for some reason something is failing?

The message looks very broad.

[dmlloyd]

It's tricky... AppCDS is definitely not a part of the platform spec. So, it doesn't make sense to fail the build unless we want to make it a requirement.

That said, how can we detect the possible reasons for failing when there isn't even a specification for it? In fact Quarkus doesn't even fail when AppCDS generation fails, it just prints a warning (the one that the code in the PR looks for).

I know how to make the check even less strict (change it to assume that the log contains e.g. AppCDS successfully created at). However I don't know of any way to make it more strict (in other words, to detect specific kinds of failures and trigger the build failure based on that). I'm open to ideas and would gladly produce a follow-up PR to improve this if anyone thinks of anything. I'll also poke around the AppCDS code to see if there's something we can use.