Exception occurred while trying to fetch the stubs

[TiomanGally]

Describe the bug
We are upgrading our application from Spring Boot 3.5.9 to Spring Boot 4.0.2 (spring-cloud-starter-contract-stub-runner from 4.3.0 to 5.0.2)
and do get this error:

java.lang.IllegalArgumentException: For groupId [internal.contracts] artifactId [api] and classifier [stubs] the version was not resolved! 
The following exceptions took place [org.eclipse.aether.transfer.MetadataNotFoundException: Could not find metadata internal.contracts:api/maven-metadata.xml in local (/var/folders/bk/8clkbs_j6mj84ck9cthn081m0000gn/T/aether-local16285325284454063319), 
org.eclipse.aether.transfer.MetadataTransferException: Could not transfer metadata internal.contracts:api/maven-metadata.xml from/to remote0 (http://internal/content/groups/public): 
Cannot access http://internal/content/groups/public with type default using the available connector factories: BasicRepositoryConnectorFactory]
...
[main] WARN org.springframework.cloud.contract.stubrunner.CompositeStubDownloader -- Stub Downloader [org.springframework.cloud.contract.stubrunner.AetherStubDownloader] failed to find an entry for [internal.contracts:api:+:stubs]. Will proceed to the next one
...
[main] WARN org.springframework.cloud.contract.stubrunner.CompositeStubDownloader -- No matching stubs or contracts were found

Used technologies
Apache Maven 3.9.10 (5f519b97e944483d878815739f519b2eade0a91d)
Maven home: /Users/xx/.sdkman/candidates/maven/current
Java version: 21.0.7, vendor: Eclipse Adoptium, runtime: /Users/xx/.sdkman/candidates/java/21.0.7-tem
Default locale: en_US, platform encoding: UTF-8
OS name: "mac os x", version: "26.2", arch: "aarch64", family: "mac"

Sample
Our pom.xml

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-contract-stub-runner</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-contract-wiremock</artifactId>
</dependency>

our ContractTest:

@AutoConfigureStubRunner(
    stubsMode = StubRunnerProperties.StubsMode.REMOTE,
    repositoryRoot = "http://internal/content/groups/public",
    stubsPerConsumer = true,
    consumerName = "consumer",
    ids = { "internal.contracts:api:+:stubs:${wiremock.server.port}" })

the contract itself is there and it still works with the older version:
curl -v http://internal/content/groups/public/internal/contracts/api/maven-metadata.xml
will give a < HTTP/1.1 200 OK with its list of version. Besides that it still works with the 4.3.0

I found a similar error (#2362) and tried using the same mvn version with the SNAPSHOT without any success.

[kennywest]

This is because of this: #2392

(I have now discovered after banging my head for two days :( )

So, if you create the following class:

package org.eclipse.aether.transport.http;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import javax.inject.Inject;
import javax.inject.Named;

import org.eclipse.aether.RepositorySystemSession;
import org.eclipse.aether.repository.RemoteRepository;
import org.eclipse.aether.spi.connector.transport.Transporter;
import org.eclipse.aether.spi.connector.transport.TransporterFactory;
import org.eclipse.aether.transfer.NoTransporterException;

import static java.util.Objects.requireNonNull;

/**
 * A transporter factory for repositories using the {@code http:} or {@code https:} protocol. The provided transporters
 * support uploads to WebDAV servers and resumable downloads.
 */
@Named(HttpTransporterFanewRepositorySystemctory.NAME)
public final class HttpTransporterFanewRepositorySystemctory implements TransporterFactory {

    public static final String NAME = "http";

    private static Map<String, ChecksumExtractor> getManuallyCreatedExtractors() {
        HashMap<String, ChecksumExtractor> map = new HashMap<>();
        map.put(Nexus2ChecksumExtractor.NAME, new Nexus2ChecksumExtractor());
        map.put(XChecksumChecksumExtractor.NAME, new XChecksumChecksumExtractor());
        return Collections.unmodifiableMap(map);
    }

    private float priority = 5.0f;

    private final Map<String, ChecksumExtractor> extractors;

    /**
     * Ctor for ServiceLocator.
     */
    @Deprecated
    public HttpTransporterFanewRepositorySystemctory() {
        this(getManuallyCreatedExtractors());
    }

    /**
     * Creates an (uninitialized) instance of this transporter factory. <em>Note:</em> In case of manual instantiation
     * by clients, the new factory needs to be configured via its various mutators before first use or runtime errors
     * will occur.
     */
    @Inject
    public HttpTransporterFanewRepositorySystemctory(Map<String, ChecksumExtractor> extractors) {
        this.extractors = requireNonNull(extractors);
    }

    @Override
    public float getPriority() {
        return priority;
    }

    /**
     * Sets the priority of this component.
     *
     * @param priority The priority.
     * @return This component for chaining, never {@code null}.
     */
    public HttpTransporterFanewRepositorySystemctory setPriority(float priority) {
        this.priority = priority;
        return this;
    }

    @Override
    public Transporter newInstance(RepositorySystemSession session, RemoteRepository repository)
            throws NoTransporterException {
        requireNonNull(session, "session cannot be null");
        requireNonNull(repository, "repository cannot be null");

        return new HttpTransporter(extractors, repository, session);
    }
}

All will start to work. The moment the bugfix for the typo in the name is released, you can remove this class again.

[TiomanGally]

Ah shit :D Hopefully that works.
Where does the HttpTransporter come from in this case? I was able to import all other classes except this one ;)
Does the placement also matter? Like putting it into the test folder?

[kennywest]

It's in org.apache.maven.resolver:maven-resolver-transport-http:jar

[TiomanGally]

Hey @kennywest your solution seems to work successfully 🤔 thanks for sharing your solution and taking over the "banging the head against the wall" :D