djl: EngineException when running in GraalVM Native Image

Description

Please see this updated project: https://github.com/murphye/djl-demo/blob/master/pneumonia-detection-quarkus/README.md

I have two endpoints:

/detect will attempt to run the model, and will fail with the following error:

Caused by: ai.djl.engine.EngineException: No deep learning engine found.
Please refer to https://github.com/awslabs/djl/blob/master/docs/development/troubleshooting.md for more details.
        at ai.djl.engine.Engine.getInstance(Engine.java:90)
        at ai.djl.repository.zoo.Criteria$Builder.<init>(Criteria.java:193)
        at ai.djl.repository.zoo.Criteria.builder(Criteria.java:173)
        at com.example.ExampleResource.detect(ExampleResource.java:45)

/check will print out information showing that the TensorFlow Engine has been loaded properly.

>>>>>>>> ZooProvider: ai.djl.repository.zoo.DefaultZooProvider [models/saved_model:ai.djl.localmodelzoo:saved_model [
        ai.djl.localmodelzoo:saved_model:N/A {}

]]
>>>>>>>> Engine: TensorFlow

There is a contradiction of information here as TensorFlow Engine is loading, but still doesn’t work. This only occurs when running in Native mode, as JVM mode is OK

I am not sure how to proceed. I suggest trying to add more debugging info to DJL to understand what is happening. Quarkus team will have debugger support soon.

How to Reproduce?

See instructions https://github.com/murphye/djl-demo/blob/master/pneumonia-detection-quarkus/README.md

Run the two endpoints and observe the logs.

What have you tried to solve it?

These configs enable the ServiceLoader mechanism:

1. https://github.com/murphye/djl-demo/blob/master/pneumonia-detection-quarkus/src/main/resources/reflection-config.json
2. https://github.com/murphye/djl-demo/blob/master/pneumonia-detection-quarkus/src/main/resources/resources-config.json

Also see https://github.com/murphye/djl-demo/blob/master/pneumonia-detection-quarkus/src/main/resources/application.properties

Environment Info

Using Maven rather than Gradle as it provides error messages that Gradle does not for Native compilation. Using Mac and GraalVM 20.1.0 with Quarkus 1.5.1.Final