Using gradlew to build backend fails with exception

English Forum Software-Development
1

Hi there,

my name is Tobi, I’m new to OpenEMS, trying to get my first backend test build up and running. I’m building on a Devuan Chimaera (equiv. Debian Bullseye) machine, first using OpenJDK 11, but after reading Bug when launching openems installed OpenJDK 14. Still I get an exception when trying to build vanilla backend as pulled from develop branch. Running with --stacktrace is of no real help to me either. So as I’m also new to gradle, I could use some pointer on what I’m doing wrong. Please see build command output below…

~/git/github/openems$ ./gradlew buildBackend

> Task :io.openems.backend.application:export.BackendApp FAILED
error : Bundle file “/home/tobi/git/github/openems/io.openems.backend.b2brest/generated/io.openems.backend.b2brest.jar” does not exist, given error is null
error : Bundle file “/home/tobi/git/github/openems/io.openems.backend.b2bwebsocket/generated/io.openems.backend.b2bwebsocket.jar” does not exist, given error is null
error : Bundle file “/home/tobi/git/github/openems/io.openems.backend.core/generated/io.openems.backend.core.jar” does not exist, given error is null
error : Bundle file “/home/tobi/git/github/openems/io.openems.backend.edgewebsocket.impl/generated/io.openems.backend.edgewebsocket.impl.jar” does not exist, given error is null
error : Bundle file “/home/tobi/git/github/openems/io.openems.backend.metadata.dummy/generated/io.openems.backend.metadata.dummy.jar” does not exist, given error is null
error : Bundle file “/home/tobi/git/github/openems/io.openems.backend.metadata.file/generated/io.openems.backend.metadata.file.jar” does not exist, given error is null
error : Bundle file “/home/tobi/git/github/openems/io.openems.backend.metadata.odoo/generated/io.openems.backend.metadata.odoo.jar” does not exist, given error is null
error : Bundle file “/home/tobi/git/github/openems/io.openems.backend.timedata.dummy/generated/io.openems.backend.timedata.dummy.jar” does not exist, given error is null
error : Bundle file “/home/tobi/git/github/openems/io.openems.backend.timedata.influx/generated/io.openems.backend.timedata.influx.jar” does not exist, given error is null
error : Bundle file “/home/tobi/git/github/openems/io.openems.backend.uiwebsocket.impl/generated/io.openems.backend.uiwebsocket.impl.jar” does not exist, given error is null
error : Bundle file “/home/tobi/git/github/openems/io.openems.shared.influxdb/generated/io.openems.shared.influxdb.jar” does not exist, given error is null

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ‘:io.openems.backend.application:export.BackendApp’.
> /home/tobi/git/github/openems/io.openems.backend.application/BackendApp.bndrun export failure

2

Hi Tobi,

thanks for getting in touch. I am not an expert (or a fan…) of gradle, either. It just happens to be the default in a bndtools environment for OSGi. As a start I would always recommend using Eclipse IDE.

Regarding you question: we are still building on Java 8, as OpenEMS targets embedded devices and their software is often a little bit behind. That being said, I am sure we will have to discuss this in the community to target a newer versions soon. I quickly changed our travis build to use OpenJDK 11 and 14. Both failed indeed (OpenJDK 14: Travis CI - Test and Deploy with Confidence, OpenJDK 11: Travis CI - Test and Deploy with Confidence) - even if the errors seem to be mainly Javadoc related, so should be a rather easy fix.

Sorry for not being able to help directly with this problem. In my point of view, you could either:

Regards,
Stefan

3

Hi Stefan,

thanks for your help. Seems it could be more valuable than what you might have expected. As I am not (possibly yet) a fan of Eclipse, I’d choose to take route 2 (Fix the bugs in the build). I just ran ‘gradlew build -x test’ which yielded into a ‘BUILD SUCCESSFUL’. So as I did some more investigation before receiving your reply, I knew that the problem was that some subproject JARs didn’t get built. After that ‘BUILD SUCCESSFUL’ I just gave building backend another try (gradlew buildBackend), and guess… now it builds successfully :slight_smile: So I think there might be an error or compatibility issue of gradle/bnd build with OpenJDK 11+ which prevents some JARs from being built. If I find it I’d prepare a PR on Github, but first of all I’ll try to proceed with that backend build.

Thank you!

Best regards,
Tobi

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