Maven "source release 17 requires target release 17" - Fix in CI

javac rejected a source level newer than the requested bytecode target. You set maven.compiler.source higher than maven.compiler.target, which is not allowed - the target cannot be older than the source.

What this error means

Compilation fails immediately with error: source release 17 requires target release 17. The numbers differ in the message because source was bumped without bumping target (or release was mixed with the older flags).

maven

[ERROR] Failed to execute goal
org.apache.maven.plugins:maven-compiler-plugin:3.13.0:compile (default-compile)
on project app: Fatal error compiling: error: source release 17 requires
target release 17 -> [Help 1]

Common causes

source higher than target

A bump of maven.compiler.source to 17 without moving maven.compiler.target leaves target at 11, which javac forbids.

release mixed with source/target

Setting maven.compiler.release and also leaving stale source/target properties produces inconsistent flags.

Inherited property only partly overridden

A parent POM sets both; a child overrides only one, splitting source and target apart.

How to fix it

Use a single release property

Prefer maven.compiler.release so source and target are always consistent and the platform API is enforced.

pom.xml

<properties>
  <maven.compiler.release>17</maven.compiler.release>
</properties>

Keep source and target equal

If you must use the older flags, set both to the same level.

pom.xml

<properties>
  <maven.compiler.source>17</maven.compiler.source>
  <maven.compiler.target>17</maven.compiler.target>
</properties>

Remove stale inherited overrides

Delete leftover source/target when switching a module to release.

Terminal

mvn -X compile | grep -i 'compiler.\(source\|target\|release\)'

How to prevent it

Standardize on maven.compiler.release across all modules.
Avoid mixing release with source/target in the same module.
Pin the compiler level in the parent POM and do not partially override it.