Plugins 08_Web, ContentIO, ODFSync, ODFWeb, UserDirectory defines in their test/environments/config.xml the line :

<cms.solr.core.url>http://localhost:8983/solr</cms.solr.core.url> 

If they do not need Solr, putting

<cms.solr.core.url>http://localhost:${solrPort}/solr</cms.solr.core.url> 

as in CMS will solve it, even though some tests do not use new framework, as long as they do not effectively need Solr of course.