Jpype version 1.6.0 not compatible with JIDT

[Maria Pope]

Mostly putting this out there as a PSA, since I spent some time today trying to figure out why a new setup wasn't working. The latest jpype version (released July of this year) only supports Java 8 and newer, so won't work with JIDT which uses Java 7. As long as you don't update your jpype you'll be fine, but maybe worth putting a note for new installers?

[Joseph Lizier]

Thanks Maria, this is an important pickup. In principle I'm trying to target as early a JDK as possible, to support anyone with really old setups (there are more than you'd expect), but when dependencies like this move along then we've got to move with them! I was planning to move the targetting to Java 8 soon anyway, so this is a good excuse. Testing is fine for me, so I'll create a new release shortly. 

In the meantime, can you share any link you have on what jpype is supporting in terms of Java classes it runs being version >= 8? The user guide https://jpype.readthedocs.io/en/latest/userguide.html mentioning Java version for Jpype seems to be about what it needs from the JDK that it runs on (which it suggests should be >= 11) rather than classes it will run

--joe
+61 408 186 901 (Au mobile)

On Thu, 16 Oct 2025 at 09:21, Maria Pope <pop...@uchicago.edu> wrote:

Mostly putting this out there as a PSA, since I spent some time today trying to figure out why a new setup wasn't working. The latest jpype version (released July of this year) only supports Java 8 and newer, so won't work with JIDT which uses Java 7. As long as you don't update your jpype you'll be fine, but maybe worth putting a note for new installers?

--
JIDT homepage: https://github.com/jlizier/jidt
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[Maria Pope]

Hi Joe,

Yes for sure! I found it on the install page: https://jpype.readthedocs.io/en/latest/install.html#binary-install where they say they've tested it for Java 8-13. I guess that doesn't necessarily guarantee that it doesn't work for Java 7... So for more detail, in case it's helpful: when I installed jpype 1.6.0 I kept getting an error that jpype could not find the org.jpype.jar file (I had never seen this error before, and had never had an issue with jpype not working immediately after a conda install). The only possibility I couldn't rule out in the end was that the new version wasn't working with Java 7, and sure enough when I downgraded jpype to version to 1.5.2 it resolved my errors completely and JIDT worked perfectly again. It is possible there's something else I'm missing, but I do think that was the only thing I changed to solve the problem.

Thank you!!

Maria

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From: jidt-d...@googlegroups.com <jidt-d...@googlegroups.com> on behalf of Joseph Lizier <joseph...@gmail.com>
Sent: Wednesday, October 15, 2025 6:28 PM
To: jidt-d...@googlegroups.com <jidt-d...@googlegroups.com>
Subject: Re: [jidt-discuss] Jpype version 1.6.0 not compatible with JIDT

 

To view this discussion visit https://groups.google.com/d/msgid/jidt-discuss/CAL81BvTYfJ7NA_6vCA%2BRjVhH-jUAt-KL9BAGjoU280ZHG%3D_cPg%40mail.gmail.com.

[Joseph Lizier]

Thanks for that Maria. That page still looks to be about the JDK that's running jpype though (which I understand), am not sure why older targetted classes would cause a problem.

Anyway, I tried jpype 1.6.0 on my platform and it's all good with the old Java 7 targetted classes! Coupled with the error message you pasted (which is about jpype resources, not the JIDT jar), I'm thinking this is a problem with your jpype 1.6 install in fact.

It seems that all's well that ends well if you're running on jpype 1.5 anyway. If you try jpype 1.6 again later, a good starting point is a new platform scheck notebook I've put together on the course branch at https://github.com/jlizier/jidt/blob/course/demos/python/platformCheck.ipynb -- you can try to run this and it will tell you exactly where its falling over.

Am running out of time to make the new distribution today, so I might leave it for now since it seems ok with jpype 1.6 at my end. But the build for Java 8 will be in the next distribution when I come back to it.

 

--joe
+61 408 186 901 (Au mobile)

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[Maria Pope]

Thanks so much!! Makes sense though-- I'm not sure what happened to my jpype installation then, but agree all's well that ends well!

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From: jidt-d...@googlegroups.com <jidt-d...@googlegroups.com> on behalf of Joseph Lizier <joseph...@gmail.com>

Sent: Wednesday, October 15, 2025 7:32 PM

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