Fix debug module publication with shadow plugin

[qwwdfsad]

It seems like Maven's BOM has never worked with shadow plugin in our previous releases: added api dependency was just too late.
It has been changed in the latest shadow plugin release and it automatically promoted all api dependencies to runtime (GradleUp/shadow#321), triggering #3345. Gradle builds were never affected though because they were primarily parsing Gradle metadata.

Resulting debug module POM

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <!-- This module was also published with a richer model, Gradle metadata,  -->
  <!-- which should be used instead. Do not delete the following line which  -->
  <!-- is to indicate to Gradle or any Gradle module metadata file consumer  -->
  <!-- that they should prefer consuming it instead. -->
  <!-- do_not_remove: published-with-gradle-metadata -->
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.jetbrains.kotlinx</groupId>
  <artifactId>kotlinx-coroutines-debug</artifactId>
  <version>1.6.3-SNAPSHOT</version>
  <packaging>pom</packaging>
  <name>kotlinx-coroutines-debug</name>
  <description>Coroutines support libraries for Kotlin</description>
  <url>https://github.com/Kotlin/kotlinx.coroutines</url>
  <licenses>
    <license>
      <name>The Apache Software License, Version 2.0</name>
      <url>https://www.apache.org/licenses/LICENSE-2.0.txt</url>
      <distribution>repo</distribution>
    </license>
  </licenses>
  <developers>
    <developer>
      <id>JetBrains</id>
      <name>JetBrains Team</name>
      <organization>JetBrains</organization>
      <organizationUrl>https://www.jetbrains.com</organizationUrl>
    </developer>
  </developers>
  <scm>
    <url>https://github.com/Kotlin/kotlinx.coroutines</url>
  </scm>
  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.jetbrains.kotlinx</groupId>
        <artifactId>kotlinx-coroutines-bom</artifactId>
        <version>1.6.3-SNAPSHOT</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>
  <dependencies>
    <dependency>
      <groupId>org.jetbrains.kotlinx</groupId>
      <artifactId>kotlinx-coroutines-core-jvm</artifactId>
      <version>1.6.3-SNAPSHOT</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>net.java.dev.jna</groupId>
      <artifactId>jna</artifactId>
      <version>5.9.0</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>net.java.dev.jna</groupId>
      <artifactId>jna-platform</artifactId>
      <version>5.9.0</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>org.jetbrains.kotlin</groupId>
      <artifactId>kotlin-stdlib-jdk8</artifactId>
      <version>1.6.21</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>net.bytebuddy</groupId>
      <artifactId>byte-buddy</artifactId>
      <version>1.10.9</version>
      <scope>runtime</scope>
    </dependency>
    <dependency>
      <groupId>net.bytebuddy</groupId>
      <artifactId>byte-buddy-agent</artifactId>
      <version>1.10.9</version>
      <scope>runtime</scope>
    </dependency>
  </dependencies>
</project>

[dkhalanskyjb]

I find this very counterintuitive: if a task is not enabled, why does its configuration contribute to anything? I propose to move the manifest block to shadowJar. If I understood correctly (and from a quick check of the resulting META-INF/MANIFEST.MF in the published JAR), this shouldn't change the result, but it would look much more clear.

[dkhalanskyjb]

Checking further, I see that this line was lost from the manifest compared to the one published to Maven Central:

Class-Path: kotlinx-coroutines-core-jvm-1.6.3.jar jna-platform-5.9.0.jar
  jna-5.9.0.jar kotlin-stdlib-jdk8-1.6.21.jar kotlin-stdlib-jdk7-1.6.21.
 jar kotlin-stdlib-1.6.21.jar kotlin-stdlib-common-1.6.21.jar annotation
 s-13.0.jar

However, deleting the locally-published repo and reverting my change, I can't make this line return. No idea what's going on.

[qwwdfsad]

Shadow jar extends the original jar task. Moved it to JAR task, it seems like the resulting published JAR contains the correct manifest.

It still worth to check it during the release tho

[dkhalanskyjb]

That's what I was proposing to do, but then I noticed the Class-Path line disappearing from the manifest.

[qwwdfsad]

The previous version also does not generate Class-Path attribute.
This is a nice catch, though I cannot convince myself that it actually ever affected anything.

[dkhalanskyjb]

This is what I observed as well, yes, just wasn't sure.

Could you please try using the debug module in a minimal project as a dependency and check that everything still works, just to be safe? We do have integration tests for using it as a Java agent, but not for just using DebugProbes, right?

[qwwdfsad]

Restored it back, created #3361

Will push integration test soon as well