 <p>Well,</p> <p>problem solved. I had to declare the resolver extension in the global scope, so that the subprojects also use it:</p> <pre><code>resolvers in Global ++= Seq( "Developer's repo" at "file://"+Path.userHome.absolutePath+"/maven2.artifacts/www" ) </code></pre> <p>Then project <code>def_symbol</code> also uses "Developer's repo" and everything works exactly as expected with versions like <code>"1.0.+"</code> or <code>"1.+"</code>.</p> <p>Not having the resolver in global scope available but having the library resolving working nevertheless was due to version 1.0.1 being available in Ivy's local cache from another build. From scratch, it would not have worked either.</p> <p>Sorry for the noise. I should have waited one more day before posting.</p>