The build script fails to generate plexus/components.xml file.

The generated build script by maven-ant-plugin fails to generate the components.xml file when run. It compiles successfully, and builds the jar (without META-INF/plexus/components.xml file). But it fails the tests saying "Component descriptor cannot be found in the component repository"

Reproduce steps -

• Get a project that generates components.xml file. One need of mine was maven-runtime at https://svn.apache.org/repos/asf/maven/shared/tags/maven-shared-components-15/maven-runtime
• run mvn ant:ant
• run ant (I ran ant -Dmaven.settings.offline=true. it doesn't matter anyway)

Here's the error log.

Buildfile: build.xml

test-offline:

get-deps:

compile:
[mkdir] Created dir: /home/me/maven-runtime/target/classes
[javac] Compiling 9 source files to /home/me/maven-runtime/target/classes

compile-tests:
[mkdir] Created dir: /home/me/maven-runtime/target/test-classes
[javac] Compiling 5 source files to /home/me/maven-runtime/target/test-classes
[copy] Copying 13 files to /home/me/maven-runtime/target/test-classes

test-junit-present:

test-junit-status:

junit-missing:

test:
[mkdir] Created dir: /home/me/maven-runtime/target/test-reports
[junit] Running org.apache.maven.shared.runtime.DefaultMavenRuntimeTest
[junit] Testsuite: org.apache.maven.shared.runtime.DefaultMavenRuntimeTest
[junit] Tests run: 1, Failures: 0, Errors: 1, Time elapsed: 0.597 sec
[junit] Tests run: 1, Failures: 0, Errors: 1, Time elapsed: 0.597 sec
[junit]
[junit] Testcase: testGetProjectPropertiesWithFileUrl took 0.259 sec
[junit] Caused an ERROR
[junit] Component descriptor cannot be found in the component repository: org.apache.maven.shared.runtime.MavenRuntime.
[junit] org.codehaus.plexus.component.repository.exception.ComponentLookupException: Component descriptor cannot be found in the component repository: org.apache.maven.shared.runtime.MavenRuntime.
[junit] at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContainer.java:323)
[junit] at org.codehaus.plexus.PlexusTestCase.lookup(PlexusTestCase.java:216)
[junit] at org.apache.maven.shared.runtime.DefaultMavenRuntimeTest.setUp(DefaultMavenRuntimeTest.java:68)
[junit]

BUILD FAILED
/home/me/maven-runtime/maven-build.xml:155: Test org.apache.maven.shared.runtime.DefaultMavenRuntimeTest failed

Total time: 3 seconds