Annotation processors not run for hot reload of multi module maven project

[Postremus]

Describe the bug
I have a multi module maven project with the following structure:

project:

• web (quarkus project)
• service (jar packaging)

The service modul has a provided dependency to an annotation processor - hibernate-jpamodelgen to be exact.
During a normal "mvn compile", the annotation processor is run, and the static metamodel gets generated.

Now, i started dev mode.
If I change one of my entity classes, the annotation processor is not run again during hot reload.

As a workaround, I can add all annotation processors to the "web" project. The are then run correctly during dev mode reload.

Alternatively, I could also change the ap to compile scope in the service project, which hints at class path problems.

Expected behavior
Compilation is done with the correct class path of a specific module. All annotation processors of a module are executed.

Actual behavior
Annotation processor is not run on dev mode hot reload.

To Reproduce

1. Download the reproducer project:
   ap-test.zip
2. Execute mvn clean compile quarkus:dev on the main project (ap-test), and open http://localhost:8080/hello in your browser
3. You will see output like [id, ID]. These are all fields currently in the static metamodel of the ExampleEntity class. The metamodel gets generated by the annotion processor.
4. Open the ExampleEntity class, and add/remove attributes.
5. Reload the browser page.
6. No change to the displayed metamodel fields.

If you now restart dev mode (mvn clean compile quarkus:dev), the change in metamodel is shown.

If you change the hibernate-jpamodelgen to compile scope, it is correctly re run on hot reload.

Environment (please complete the following information):

• Output of uname -a or ver:
  Linux martin 5.4.0-40-generic Arc - request context propagation #44-Ubuntu SMP Tue Jun 23 00:01:04 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
• Output of java -version:
  openjdk 11.0.7 2020-04-14 LTS
  OpenJDK Runtime Environment Zulu11.39+15-CA (build 11.0.7+10-LTS)
  OpenJDK 64-Bit Server VM Zulu11.39+15-CA (build 11.0.7+10-LTS, mixed mode)
• Quarkus version or git rev:
  1.6.0.Final
• Build tool (ie. output of mvnw --version or gradlew --version):
  Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f)
  Maven home: /home/martin/.sdkman/candidates/maven/current
  Java version: 11.0.7, vendor: Azul Systems, Inc., runtime: /home/martin/.sdkman/candidates/java/11.0.7-zulu
  Default locale: en_US, platform encoding: UTF-8
  OS name: "linux", version: "5.4.0-40-generic", arch: "amd64", family: "unix"

[famod]

@Postremus Thanks for reporting this!

Unfortunately, this is a long standing (unresolved) issue: #1502
So I'll have to close this as a duplicate.

[famod]

Sorry, I just realized that you are already using the provided workaround that was mentioned here: #1502 (comment)
Btw, I ran into #1502 with hibernate-jpamodelgen myself but I did not want to add it as a dependency since it brings in jaxb which has a specific Quarkus-module that shall be used instead and I wanted to avoid conflicts. See also: #1502 (comment)

I'll reopen this so that @aloubyansky can have a look. But I suppose this will be tricky since provided dependencies are not propagated to downstream modules.
You could add it to the root parent, but that might also cause inconsistencies...

[aloubyansky]

Yes, it's a good one. We need to properly setup the classpath for each module.

[famod]

@Postremus

You could add it to the root parent

Have you ever tried this?

[Postremus]

Closing this one. This is deprecated now that one is supposed to declare annotation processors using the compiler plugin

[Postremus]

If I define the annotationProcessorPaths on the compiler-plugin of different modules, they are not executed by the quarkus dev mode hot reload.

If I define my compiler-plugin configuration additionally on the module housing my quarkus-maven-plugin, then the annotation processors are executed for each hot reload.

@famod fyi

<plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <annotationProcessorPaths>
                        <path>
                            <groupId>org.hibernate.orm</groupId>
                            <artifactId>hibernate-jpamodelgen</artifactId>
                        </path>
                    </annotationProcessorPaths>
                </configuration>
            </plugin>