External _JAVA_OPTIONS environment variable sourcing for self-contained applications

[Alan Bateman]

On 09/05/2024 08:03, David Holmes wrote:
>
> How does such a jpackaged application actually launch/load the JVM? 
> I'm wondering if there is a way to insert a new "shell" environment to 
> launch the JVM without having those env vars present ... though I 
> guess there may be other env vars that your application still needs.

For modular applications, there is a jlink option to generate a launcher 
(script) for the application. That's a potential place to unset 
environment variables that shouldn't be inherited.  It may not help here 
as it sounds like this is an application image produced by jpackage with 
a native launcher, and the warning message is hidden as there is no 
console (I assume).

I think we should consider deprecating and eventually removing 
_JAVA_OPTIONS. It's always been problematic that it appends rather than 
prepend and it has issues in areas such as quoting. When 
JDK_JAVA_OPTIONS was added then we had hoped that developers would move 
from the undocumented env variable. The new env variable fixes a bunch 
of things in the areas of quoting, arg files, works with launcher 
options, and it of course prepends so it doesn't override options.

-Alan