is it possible to modify execOperations.javaExec { .. } to always have a set of jvmArgs applied?
I got a plugin (not one of mine) which has a Task and in the body of that task it uses:
execOperations.javaExec { .. }
Unfortunately the plugins task has no Provider / Property where I could set my jvmArgs to be used in that operation, so the question is, without changing the plugins code - can I somehow modify the jvmArgs of execOperations.javaExec { .. } globally and/or for that usage in that task?
No, that is a task implementation detail.
If the task author does not provide a way to configure it, there is no way to configure it.
Well, there is JAVA_TOOL_OPTIONS environment variable that you can set and that will be picked automatically by any started JVM. But that will then be effective for each and every JVM started while that environment variable is set.