Pipelining prevents Java compilation with compileOrder := JavaThenScala config

[guersam]

steps

1. Checkout https://github.com/guersam/sbt-debug-pipelined-hybrid-project.
2. Run $ sbt run.

problem

It fails due to a missing Java class. The incremental compilation log shows that the Java source code is not compiled.

expectation

It prints:

Hello world!
42

notes

1. Both usePipelining := true and compileOrder := CompilerOrder.JavaThenScala settings are needed to reproduce
2. It's reproducible both in sbt 1.9.9 and 1.10.0-RC2.
3. It happens with both Scala 2 and 3.
4. CI result with sbt 'last compileIncremental' log

[info] welcome to sbt 1.10.0-RC2 (Eclipse Adoptium Java 11.0.22)
[info] loading project definition from /home/runner/work/sbt-debug-pipelined-hybrid-project/sbt-debug-pipelined-hybrid-project/project
[info] loading settings for project root from build.sbt ...
[info] set current project to sbt-pipelining-debug (in build file:/home/runner/work/sbt-debug-pipelined-hybrid-project/sbt-debug-pipelined-hybrid-project/)
[debug] [zinc] IncrementalCompile -----------
[debug] IncrementalCompile.incrementalCompile
[debug] previous = Stamps for: 0 products, 0 sources, 0 libraries
[debug] current source = Set(${BASE}/src/main/java/example/JavaClass.java, ${BASE}/src/main/scala/example/Main.scala)
[debug] > initialChanges = InitialChanges(Changes(added = Set(${BASE}/src/main/java/example/JavaClass.java, ${BASE}/src/main/scala/example/Main.scala), removed = Set(), changed = Set(), unmodified = ...),Set(),Set(),API Changes: Set())
[debug] Full compilation, no sources in previous analysis.
[debug] all 2 sources are invalidated
[debug] Initial set of included nodes: 
[debug] Recompiling all sources: number of invalidated sources > 50.0 percent of all sources
[debug] compilation cycle 1
[info] compiling 1 Scala source and 1 Java source to /home/runner/work/sbt-debug-pipelined-hybrid-project/sbt-debug-pipelined-hybrid-project/target/scala-3.4.1/classes ...
[debug] Returning already retrieved and compiled bridge: /home/runner/.cache/coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala3-sbt-bridge/3.4.1/scala3-sbt-bridge-3.4.1.jar.
[debug] [zinc] Running cached compiler 5[9](https://github.com/guersam/sbt-debug-pipelined-hybrid-project/actions/runs/8747771673/job/24006749488#step:5:10)c3d61b for Scala Compiler version 3.4.1
[debug] [zinc] The Scala compiler is invoked with:
[debug] 	-classpath
[debug] 	/home/runner/work/sbt-debug-pipelined-hybrid-project/sbt-debug-pipelined-hybrid-project/target/scala-3.4.1/classes:/home/runner/.cache/coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala3-library_3/3.4.1/scala3-library_3-3.4.1.jar:/home/runner/.cache/coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.[12](https://github.com/guersam/sbt-debug-pipelined-hybrid-project/actions/runs/8747771673/job/24006749488#step:5:13)/scala-library-2.13.12.jar
[debug] Compilation failed
[error] (Compile / compileIncremental) Compilation failed