A required class was missing while executing org.springframework.cloud:spring-cloud-contract-maven-plugin:4.2.1:generateTests: org/springframework/core/io/ProtocolResolver

[jakub-bochenski]

Describe the bug
Maven build fails for no apparent reason with the above error message.

Apache Maven 3.9.9 (8e8579a9e76f7d015ee5ec7bfcdc97d260186937)
Java version: 21.0.7, vendor: Ubuntu, runtime: /usr/lib/jvm/java-21-openjdk-amd64

[ERROR] Failed to execute goal org.springframework.cloud:spring-cloud-contract-maven-plugin:4.2.1:generateTests (default-generateTests) on project example: Execution default-generateTests of goal org.springframework.cloud:spring-cloud-contract-maven-plugin:4.2.1:generateTests failed: A required class was missing while executing org.springframework.cloud:spring-cloud-contract-maven-plugin:4.2.1:generateTests: org/springframework/core/io/ProtocolResolver
[ERROR] -----------------------------------------------------
[ERROR] realm =    extension>org.springframework.cloud:spring-cloud-contract-maven-plugin:4.2.1
[ERROR] strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy

[jakub-bochenski]

Removing spring-core from repository and forcing a download again fixed it. So it's most likely caused by #2134