d2 rendering does not work

[snowe2010]

With this example project you can see that d2 rendering doesn't work. Testing with the linked project you can see that the asciidoctor-diagram gem generates both diagrams correctly (d2 and ditaa), while the asciidoctorJ task fails to generate the d2 diagram

d2asciidoctorj.zip

simply run ./gradlew asciidoctor and look at the build/docs/asciidoc/pages/index.html file and you will see a generated ditaa diagram, but the d2 diagram is not generated, and is a plain block inline in the html.

to compare to asciidoctor-diagram run
bundle
to install the gems needed and then run
./gradlew asciidoctorFromGem
and look at the docs/modules/ROOT/pages/index.html file to see the diagram has been generated correctly with the gem.

I initially thought I was doing something wrong because this user #35 seemed to get it working, but this is about as simple of an example as I can create and yet it still doesn't work. Either the docs are wrong or this just doesn't work.

[robertpanzer]

I am able to generate a d2 diagram from a unit test from asciidoctorj-diagram.
I am not sure atm why it doesn't work with the gradle plugin.

[robertpanzer]

Even when running asciidoctorj -r asciidoctor-diagram index.adoc the d2 diagram is built for me.
I would recommend opening an issue at the asciidoctor/asciidoctor-gradle-plugin.

[snowe2010]

ok, thank you. reported there. asciidoctor/asciidoctor-gradle-plugin#741