Quarkus: @Produces annotated methods that are not consumed not ignored and result in failed build

[jordanglassman]

Describe the bug
Issue described here persists under 0.20.0.

Expected behavior
When using a class with method annotated with @Produces, even if never "produced", expect successful build.

Actual behavior
Build fails with misleading error message:

[ERROR] Failed to execute goal io.quarkus:quarkus-maven-plugin:0.20.0:build (default) on project injector-jira-service: Failed to build a runnable JAR: Failed to build a runner jar: Failed to augment application classes: Build failure: Build failed due to errors
[ERROR]     [error]: Build step io.quarkus.arc.deployment.ArcProcessor#generateResources threw an exception: java.lang.IllegalArgumentException: Must be a Class or String, got null
[ERROR] -> [Help 1]
[ERROR]

To Reproduce
Steps to reproduce the behavior:

Simple reproducer:

package service;

@ApplicationScoped
public class SomeResource {
    @Inject
    SomeService someService;

    public void doSomething() {
    }
}

package service;

import client.SomeProvider;
import javax.enterprise.context.ApplicationScoped;
import javax.enterprise.context.RequestScoped;
import javax.inject.Inject;

@ApplicationScoped
public class SomeService {
    @Inject
    @RequestScoped
    SomeProvider someProvider;

    //  as a workaround, the "produced" but unused bean can be instantiated but ignored to silence this error
    // @Inject
    // @RequestScoped
    // SomeClient someClient;

    public void doSomething() {
    }
}

package client;

import java.net.URI;
import javax.enterprise.context.RequestScoped;
import javax.enterprise.inject.Produces;
import org.eclipse.microprofile.rest.client.RestClientBuilder;

@RequestScoped
public class SomeProvider {

    @Produces
    @RequestScoped
    public SomeClient getClient() {
        return RestClientBuilder
                .newBuilder()
                .baseUri(URI.create("http://example.com"))
                .build(SomeClient.class);
    }
}

package com.cloudbees.sdm.injector.jira.client;

import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;

@Consumes("application/json")
@Produces("application/json")
public interface SomeClient {

    @GET
    @Path("/rest/api/lols")
    void getLols();
}

Add classes to project and build with maven.

Configuration
N/A

Environment (please complete the following information):

• Output of uname -a or ver:

$ uname -a
Darwin ip-192-168-1-137.ec2.internal 18.2.0 Darwin Kernel Version 18.2.0: Mon Nov 12 20:24:46 PST 2018; root:xnu-4903.231.4~2/RELEASE_X86_64 x86_64

• Output of java -version:

$ java -version
java version "1.8.0_221"
Java(TM) SE Runtime Environment (build 1.8.0_221-b11)
Java HotSpot(TM) 64-Bit GraalVM EE 19.1.1 (build 25.221-b11-jvmci-19.1-b01, mixed mode)

• Quarkus version or git rev: 0.20.0

[geoand]

Hi, just a quick question, have you tried with the latest Quarkus 0.22.0?

[mkouba]

Hm, but SomeClient is proxyable.... I'll try to reproduce the issue and we'll see what the real problem is.

[mkouba]

By the way, an injection point (e.g. SomeService#someProvider) should not declare a scope annotation -> it will be simply ignored.

[mkouba]

It turns out we have a bug in the bean removal algorithm. If there's a bean that declares an unused producer we remove the declaraing bean although it's injected somewhere.