Skip to content

build(log4j2): Pin compilation to JDK 8 via Maven Toolchains#616

Open
rschmitt wants to merge 1 commit into
aws:mainfrom
rschmitt:toolchains
Open

build(log4j2): Pin compilation to JDK 8 via Maven Toolchains#616
rschmitt wants to merge 1 commit into
aws:mainfrom
rschmitt:toolchains

Conversation

@rschmitt
Copy link
Copy Markdown

@rschmitt rschmitt commented May 23, 2026

Release 1.6.3 was built on a JDK that does not run annotation processors by default, which silently dropped the Log4j2 plugin descriptor (META-INF/.../Log4j2Plugins.dat) for LambdaAppender, LambdaTextFormat, and LambdaJsonFormat. The published artifact was broken at runtime: log4j could not resolve <Lambda>, <LambdaTextFormat>, or <LambdaJsonFormat> elements in user log4j2.xml configurations.

Configure maven-toolchains-plugin to require a JDK 8 toolchain so javac comes from a JDK that runs annotation processors by default, regardless of which JVM Maven is invoked under. The version range [1.8,9) matches both "1.8" and "8".

The existing GitHub Actions workflow at .github/workflows/aws-lambda-java-log4j2.yml uses actions/setup-java@v5 with java-version: 8 and distribution: corretto. setup-java@v5 auto-generates a ~/.m2/toolchains.xml entry with 8, which the [1.8,9) range matches, so no workflow changes are required.

When no matching JDK 8 toolchain is available, the build now fails fast at the validate phase with a clear "Cannot find matching toolchain definitions" error instead of silently producing an artifact missing its plugin descriptor.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Release 1.6.3 was built on a JDK that does not run annotation processors
by default, which silently dropped the Log4j2 plugin descriptor
(META-INF/.../Log4j2Plugins.dat) for LambdaAppender, LambdaTextFormat,
and LambdaJsonFormat. The published artifact was broken at runtime:
log4j could not resolve <Lambda>, <LambdaTextFormat>, or
<LambdaJsonFormat> elements in user log4j2.xml configurations.

Configure maven-toolchains-plugin to require a JDK 8 toolchain so javac
comes from a JDK that runs annotation processors by default, regardless
of which JVM Maven is invoked under. The version range [1.8,9) matches
both "1.8" and "8".

The existing GitHub Actions workflow at
.github/workflows/aws-lambda-java-log4j2.yml uses actions/setup-java@v5
with java-version: 8 and distribution: corretto. setup-java@v5
auto-generates a ~/.m2/toolchains.xml entry with <version>8</version>,
which the [1.8,9) range matches, so no workflow changes are required.

When no matching JDK 8 toolchain is available, the build now fails fast
at the validate phase with a clear "Cannot find matching toolchain
definitions" error instead of silently producing an artifact missing its
plugin descriptor.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

1 participant