including test-jar in the runtime scope - maven

Question

i got a war-project and in the test-jar of it, we have aside of the jUnit testcases also the mocks to the neighbor systems (for instance, the roles and users management system).
and we have a maven profile called mocking that adds the test-jar dependency to the war-project, at runtime, so that the mocks are available for the developer, but do not end up by error in production.
<profile>
<id>mocking</id>
<activation>
<activeByDefault>false</activeByDefault>
</activation>
<dependencies>
<dependency>
<groupId>${project.groupId}</groupId>
<artifactId>${project.artifactId}</artifactId>
<version>${project.version}</version>
<type>test-jar</type>
<scope>runtime</scope>
</dependency>
...
not very clean, i know, but we did not want to have just another artifact for only a hand full of mock clases, and it worked so far well with Maven 3.3.9.
now we need a feature of Maven 3.5.0, so i updated to the latest Maven 3.6.2 and get following error:
The project com.my-project:web:0.0.1-SNAPSHOT has 1 error:
'dependencies.dependency.[com.my-project:web:0.0.1-SNAPSHOT]' for com.my-project:web:0.0.1-SNAPSHOT is referencing itself.
which is kind of borderline case.
imho, and since the dependency is of scope runtime, it should be allowed.
is this a bug?
can anyone figure out a better way to achieve this?
many thanks
Michael
UPDATE 20191125:
Without full pom files or at least an example which looks very like your original projects it's hard to guess....
Here a small pom-file to reproduce the problem:
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>my.project</groupId>
<artifactId>test</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<name>test</name>
<dependencies>
<dependency>
<groupId>${project.groupId}</groupId>
<artifactId>${project.artifactId}</artifactId>
<version>${project.version}</version>
<type>test-jar</type>
<scope>runtime</scope>
</dependency>
</dependencies>
</project>
with that file, and nothing else, mvn compile works fine with v3.3.9 but breaks with v3.6.2

Answer 1

If you use the normal setup for creating a test-jar this implies the test-jar is created as supplemental artifact to your usual artifacts which needed to be distinguished from each other which has to be achieved by using the <classifier>tests</classifier>.