Analysis

The common pattern observed in similar fixed build failures is that the maven/pombump step is failing because it can't find a pom.xml file. This typically happens when a project doesn't use Maven as its primary build system. In the fixed examples:

1. For Cassandra, which uses Ant build system, the fix was to specify the location of a pom file using the "pom" parameter.
2. For Selenium, which uses Bazel build system, the fix was to remove the maven/pombump step entirely and use patching to handle dependency updates.

In the current Solr build failure, the issue is similar - Solr uses Gradle as its primary build system, not Maven, so there's no pom.xml file at the repository root where maven/pombump is looking for it.

Explanation

The fix involves removing the maven/pombump step entirely from the pipeline since Solr uses Gradle as its build system, not Maven. This is evident from the build steps that follow the pombump step, which use Gradle commands like ./gradlew --write-locks and ./gradlew assembleDist.

Removing the maven/pombump step is appropriate because:

1. Solr is primarily built with Gradle, which is confirmed by the presence of Gradle build files and the usage of ./gradlew commands in the build pipeline.
2. The manual version updates for dependencies are already being handled directly in the pipeline by editing the versions.props file with sed commands.
3. The build system successfully runs the Gradle commands after the pombump step fails, indicating that Gradle is the correct build tool for this project.

Unlike the Cassandra example where they specified a pom file location, there doesn't appear to be a need to use Maven at all for the Solr build. The Gradle system handles all the dependency resolution and building tasks.

Alternative Approaches

• Instead of removing the maven/pombump step, we could add a 'pom' parameter to point to a specific pom.xml file if one exists somewhere in the Solr repository structure, similar to the Cassandra fix.
• If maven/pombump is still needed for some reason, we could create a minimal pom.xml file as part of the build process before running the maven/pombump step.