Galo: are you using plain vanilla Jetty, or are you using Jetty Plus? the examples for "Configuring Solr Home with JNDI" and "Multiple Solr Webapps" both require Jetty Plus (because the JNDI support only exists in the extra libraries JettyPlus provides)
That may explain the missing method call when trying to do addEnvEntry if you can't use Jetty Plus to have JNDI support, or if the latest version of Jetty doesn't support JNDI anymore (can't imagine that would be the case) then you might be able to find a way to set teh solr.solr.home system property on a per webapp basis ... how to do that in a Jetty config may be a better question for the Jetty user community. (if you do discover that the config syntax for JNDI has changed significantly in the latest versions of Jetty, by all means please update the wiki ... we'd probably want seperate sections for the different versions since not everyone will be running the latest, but it's still good info to have) -Hoss
