[Issue]: System Java Problem

[kngwyu]

Summary

I got this error when building app by ./app target backAndForth and ./app build

FAILURE: Build failed with an exception.

• What went wrong:
  Could not determine the dependencies of task ':backAndForth:packageDebug'.

Could not create task ':backAndForth:compileDebugJavaWithJavac'.
Failed to calculate the value of task ':backAndForth:compileDebugJavaWithJavac' property 'javaCompiler'.
> Toolchain installation '/usr/lib/jvm/java-21-openjdk-amd64' does not provide the required capabilities: [JAVA_COMPILER]

Current state

Build fails when ./app tries to use system instlled jdk.

Expected state

Build successes or at least it should tell me to use different jdk.

[topherbuckley]

Addressed in d1b7c4c currently based on the tutorial branch, to be merged to main at a later time. I'll close this after merging to main.

Root cause: their /usr/lib/jvm/java-21-openjdk-amd64 installation was a JRE/runtime-only install, not a full JDK.

The key part of the Gradle error is:

Toolchain installation '/usr/lib/jvm/java-21-openjdk-amd64' does not provide the required capabilities:
[JAVA_COMPILER]

Gradle found Java there, but not a Java compiler. On this machine that exact path has:

/usr/lib/jvm/java-21-openjdk-amd64/bin/java

but does not have:

/usr/lib/jvm/java-21-openjdk-amd64/bin/javac

A full JDK must include javac. Android Studio’s bundled JDK worked because it is a complete JDK/JBR distribution,
not just a runtime.