Need help on debugging No matching variant error

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1

I am trying to build an android SDK but I get this error while syncing.

A problem occurred configuring project ':mymodule'.
> Could not resolve all files for configuration ':mymodule:classpath'.
   > Could not resolve mypkg:mylib:1.0.0.
     Required by:
         project :mymodule
      > No matching variant of mypkg:mylib:1.0.0 was found. The consumer was configured to find a runtime of a library compatible with Java 8, packaged as a jar, and its dependencies declared externally, as well as attribute 'org.gradle.plugin.api-version' with value '7.5.1' but:
          - Variant 'apiElements' capability mypkg:mylib:1.0.0 declares a library, packaged as a jar, and its dependencies declared externally:
              - Incompatible because this component declares an API of a component compatible with Java 11 and the consumer needed a runtime of a component compatible with Java 8
              - Other compatible attribute:
                  - Doesn't say anything about org.gradle.plugin.api-version (required '7.5.1')
          - Variant 'runtimeElements' capability mypkg:mylib:1.0.0 declares a runtime of a library, packaged as a jar, and its dependencies declared externally:
              - Incompatible because this component declares a component compatible with Java 11 and the consumer needed a component compatible with Java 8
              - Other compatible attribute:
                  - Doesn't say anything about org.gradle.plugin.api-version (required '7.5.1')

I am using Gradle 7.5.1 and as far as possible specified usage of Java 11. Any idea how to debug further or fix this issue?

2

Hard to say without seeing the build.
But I’d say you are running Gradle with Java 8 and try to use the plugin mypkg:mylib that is compiled with minimum version Java 11.

3

Thanks for your reply. Forcing mylib to use Java 8 does solve the problem. However, what this means “Gradle with Java 8”? A given Gradle version supports a range of Java versions. How do I know “Java 8” is used here? For mylib, I would use android → compileOptions → source/target compatibility.

4

Gradle is a Java program.
You run it with some Java version.
I guessed that you are running it with Java 8 when getting that error while trying to use some plugin that was compiled with minimum Java version 11.