Beware that this does not disable local p2 cache, so if your first build did redownload most dependencies, and the second could get them from cache, it could be a reason why you save time, independently of -Dtycho.localArtifacts=ignore.Tested this key in relation to https://issues.jboss.org/browse/JBIDE-13411 and it looks like adding to buuld command makes build (w/o running tests) twice faster for me.