Currently, if you try to run release:prepare on a multimodule project after removing any of that build's artifacts from the local repository, it will fail. Investigate why release:prepare needs the multimodule artifacts installed in the local repository before it can succeed.
To reproduce, comment the following line in it2002/test.sh:
mvn clean install
NOTE: This may have to do with the version resolution code, which is used to resolve SNAPSHOT versions.