[MCOMPILER-354] Module patching fails: case of simple single-module project

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.7.0
• Labels: Jigsaw

Environment

$ mvn -version
Apache Maven 3.5.4 (1edded0938998edf8bf061f1ceb3cfdeccf443fe; 2018-06-17T20:33:14+02:00)
Maven home: G:\software\apache-maven-3.5.4-bin\apache-maven-3.5.4
Java version: 10.0.2, vendor: Oracle Corporation, runtime: C:\Program Files\Java\jdk-10.0.2
Default locale: fr_FR, platform encoding: Cp1252
OS name: "windows 7", version: "6.1", arch: "amd64", family: "windows"

• Flags: Important
• Assignee: Unassigned
• Reporter: foo bar
• Created: 28/Jul/18 13:25
• Updated: 05/Aug/18 15:23

Description

Sometimes it can be difficult to setup maven test-scoped dependencies in a Maven multi-module project. But I think I managed to find a simple 1-module case where module patching doesn't work.

I have a single-module Java 10 project where the testCompile goal complains that Test Class A doesn't read Test Class B, which is in the same project! (but in a different package)
Of course, a class shouldn't need to be exported to a class of the same module. So maybe there is a confusion somewhere between the unnamed module, automatic modules, and explicit modules.
I think that's because of a bug in the module-patching flags passed by testCompile to javac.

My project source tree, in its simplified branch to reproduce the issue, looks shown in the project.png attachment.

Full log is attached as well as a zip of the issue reproduction branch. It can also be cloned from:

git clone https://github.com/vandekeiser/wires.git
git checkout REPORT-MCOMPILER-2
mvn clean install

The flags testCompile pass to javac.

[INFO] --- maven-compiler-plugin:3.7.0:testCompile (default-testCompile) @ wires-support ---
[DEBUG] Command line options:
    -d G:\projets\wires\wires\wires\wires-support\target\test-classes
    -classpath G:\projets\wires\wires\wires\wires-support\target\test-classes;
    --module-path G:\projets\wires\wires\wires\wires-support\target\classes;
    -sourcepath G:\projets\wires\wires\wires\wires-support\src\test\java;
                G:\projets\wires\wires\wires\wires-support\target\generated-test-sources\test-annotations;
    -s G:\projets\wires\wires\wires\wires-support\target\generated-test-sources\test-annotations
    -g -deprecation -target 10 -source 10 -encoding UTF-8 -Werror -Xlint:all,-serial
    --patch-module fr.cla.wires.support=
        G:\projets\wires\wires\wires\wires-support\target\classes;
        G:\projets\wires\wires\wires\wires-support\src\test\java;
        G:\projets\wires\wires\wires\wires-support\target\generated-test-sources\test-annotations;
    --add-reads fr.cla.wires.support=ALL-UNNAMED

The warning I get (which for me is an error):

[WARNING] /G:/projets/wires/wires/wires/wires-support/src/test/java/fr/cla/wires/support/DoesntCompile.java:[14,20]
    class fr.cla.wires.support.javac_complains_this_is_not_exported.JavacComplainsThisIsNotExported
    in module fr.cla.wires.support
    is not exported

[ERROR] COMPILATION ERROR :
warnings found and -Werror specified
[INFO] 1 error