Bug#897945: #897945 still present/breaks with Java 8

[Per Lundberg]

On 1/29/19 1:32 PM, Markus Koschany wrote:

Hi Markus and Emmanuel,

Emmanuel - the problem is that VisualVM will display its splash screen, 
then die with an error in the log about java.lang.NoSuchMethodError: 
java.nio.ByteBuffer.position(I)Ljava/nio/ByteBuffer;

>> I am sorry but OpenJDK 8 will not be supported at runtime in
>> Buster. If it works with OpenJDK 11, which it does, then we should
>> spend the remaining time before the release on more urgent issues.
> 
> I should have added that we compile for Java 9 bytecode with the
> - -Dpermit.jdk9.builds=true switch in visualvm and in
> libnb-platform18-java. No surprises here that it won't work with
> OpenJDK 8.

I am fine with this; we should just try to make the user experience a 
bit smoother.

> What we can and probably should do is to force OpenJDK 11
> by using a stricter dependency on default-jdk (>= 2:1.11) | java11-sdk
> and by also updating the 03-launcher.patch and remove the alternative
> search paths for OpenJDK 7 and OpenJDK 8. The result is that visualvm
> simply will not start anymore and quit with "No jdkhome found" if
> someone uses an unsupported JDK.

That sounds like a reasonable path: the effort should not be huge, and 
the user experience will be improved. The problem right now (with Java 
8) is that it just "dies" as described above, no error message printed. 
You have to more or less _know_ that you should go digging in 
~/.visualvm/1.4/var/log/messages.log for it. This is not so great.

But, the approach you suggest is fine. Markus, will you reopen this bug 
or should we file a new one about it, what do you prefer?
--
Best regards,
Per