Details
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Bug
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Status: Open
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Major
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Resolution: Unresolved
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3.2.0
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None
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None
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macOS Mojave 10.14.6
Description
The recently released version 3.2.0 of the Maven Archetype Plugin has broken an archetype I created. I have confirmed my archetype still works with version 3.1.2 of the plugin but my team and I normally run mvn archetype:generate ... just so we don’t have to specify a particular version of the plugin, but now Maven will pick up the 3.2.0 version of the plugin and fail. I am aware that using mvn org.apache.maven.plugins:maven-archetype-plugin:3.1.2:generate ... will work around the problem, but I’d still like to fix my archetype to work with the latest version of the plugin.
The problem appears to be that something has changed with how the class path/resources are setup with the Velocity template engine when rendering templates. I tried looking through the release notes but it just looks like version numbers were bumped, so I doesn’t seem like this was an intentional change in behavior.
The source of the problem is my archetype has a common META-INF/common-variable-definitions.vm that contains variables that are used in multiple files within the archetype. This worked great with earlier versions of the archetype plugin, each template that needed the common variable definitions simply needed a #parse( "META-INF/common-variable-definitions.vm” ) at the top of the file and then all of the usual replacements that were needed are available. Now, with the 3.2.0 version of the plugin I get the following error:
... [ERROR] ResourceManager : unable to find resource 'archetype-resources/META-INF/common-variable-definitions.vm' in any resource loader. [ERROR] #parse(): cannot find template 'archetype-resources/META-INF/common-variable-definitions.vm', called at archetype-resources/pom.xml[line 1, column 1] [INFO] ------------------------------------------------------------------------ [INFO] BUILD FAILURE [INFO] ------------------------------------------------------------------------ [INFO] Total time: 1.327 s [INFO] Finished at: 2020-08-26T16:28:24-07:00 [INFO] ------------------------------------------------------------------------ [ERROR] Failed to execute goal org.apache.maven.plugins:maven-archetype-plugin:3.2.0:integration-test (default-integration-test) on project demo-archetype: [ERROR] Archetype IT 'basic' failed: Error merging velocity templates: Unable to find resource 'archetype-resources/META-INF/common-variable-definitions.vm' [ERROR] -> [Help 1] [ERROR] [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch. [ERROR] Re-run Maven using the -X switch to enable full debug logging. [ERROR] [ERROR] For more information about the errors and possible solutions, please read the following articles: [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
The issue is that the Velocity engine now expects the common definitions file in archetype-resources/META-INF instead of a top-level META-INF directory. I tried moving the file to archetype-resources/META-INF/common-variable-definitions.vm, but I found that only worked for the “first level”, and it essentially expected that file to copied into every level of the directory hierarchy of the archetype resources that had templates to render, which makes trying to do this totally pointless, I might as well copy the definitions into the top of each file like I had done in a very early version of my archetype. I also tried using “../“ relative paths (like #parse( “../META-INF/common-variable-definitions.vm” )) in files deeper into the directory hierarchy to reference back up to a single common velocity template, but could not get that to work either.
Is there something I can do to get this working again with version 3.2.0? Or is this no something that is actually supported and I was just getting lucky before?
To help reproduce the problem I created a simple example project to demonstrate this change in behavior between the two versions of the Maven Archetype Plugin. The top-level pom.xml in the attach tar has the following properties which you can comment/uncomment to switch between a working and failing version.
<properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <!-- This version of archetype plugin works --> <!--<maven-archetype-plugin.verson>3.1.2</maven-archetype-plugin.verson>--> <!-- This version of archetype plugin does not work --> <maven-archetype-plugin.verson>3.2.0</maven-archetype-plugin.verson> </properties>
If you uncompress the attached tar and call mvn clean verify you can see how it works with 3.1.2 and fails with 3.2.0.