title: Jenkins multi-configuration project user-defined axis environment variable
body: <p>I am trying to set up a multi-configuration project in Jenkins with a single user-defined axis (call it "axis").  The value associated with each configuration would then be used to invoke top-level maven targets in <code>${axis}/pom.xml</code>.  The trouble is, I can't find the proper syntax for this, if indeed it does exist (<code>${axis}</code>, <code>$axis</code>, <code>$AXIS</code>, and <code>${env.axis}</code> all fail).  I would think it would be shell syntax, which it doesn't seem to be, but regardless it should be either simple or impossible.  Is it possible?</p>