bloop-maven-plugin

This repository holds the Maven Plugin for Bloop.

NOTE: This project was previously published as ch.epfl.scala:maven-bloop_2.13, however it's now published as ch.epfl.scala:bloop-maven-plugin. The usage remains the same.

Getting Started

• To get started please refer to the docs here.
• If you're looking for the main Bloop codebase, head over here.
• If you're interested in contributing, check out our CONTRIBUTING.md.

Known limitations

--add-exports / --add-opens and JDK-internal types

If a Java class extends or otherwise hard-depends on a JDK-internal type that is only reachable via --add-exports/--add-opens (for example a class extending jdk.javadoc.internal.tool.DocEnvImpl), Bloop can fail to compile it even though Maven succeeds, with an error such as:

java.lang.IllegalAccessError: superclass access check failed: ... cannot access
class jdk.javadoc.internal.tool.DocEnvImpl (in module jdk.javadoc) because module
jdk.javadoc does not export jdk.javadoc.internal.tool to unnamed module

This plugin does forward those options correctly: any --add-exports you set in maven-compiler-plugin's <compilerArgs> ends up verbatim in the generated java.options, so javac itself compiles fine. The failure happens afterwards, when Zinc (inside the Bloop server JVM) reflectively loads the freshly compiled classes to extract their API — that JVM was not launched with the --add-exports flag, so the class load is rejected. This is outside the reach of a per-project config file and is tracked upstream in sbt/zinc#837.

Workaround: start the Bloop server with the same flag, e.g.

export BLOOP_JAVA_OPTS="--add-exports jdk.javadoc/jdk.javadoc.internal.tool=ALL-UNNAMED"

(or set the equivalent bloop.java-opts property). This grants the export to the JVM that runs Zinc. Note it is global to the server, not per-project.