CMake External Project not Downloading
<p>I am using CMake 3.5.1 with CLion, and I am attempting to download and install an external project from a URL.  My CMakeLists.txt include:</p>

<pre><code>include(ExternalProject)
set(EXTERNAL ${PROJECT_SOURCE_DIR}/external)
ExternalProject_Add(eigen_test
        PREFIX ${EXTERNAL}/eigen
        DOWNLOAD_DIR ${EXTERNAL}/eigen/download
        SOURCE_DIR ${EXTERNAL}/eigen/src
        BINARY_DIR ${EXTERNAL}/eigen/build
        INSTALL_DIR ${EXTERNAL}/eigen/install
        URL http://bitbucket.org/eigen/eigen/get/3.2.4.tar.gz
        URL_MD5 4d0d77e06fef87b4fcd2c9b72cc8dc55
        CONFIGURE_COMMAND cd &lt;BINARY_DIR&gt; &amp;&amp; cmake -D CMAKE_INSTALL_PREFIX=$&lt;INSTALL_DIR&gt; &lt;SOURCE_DIR&gt;
        )
</code></pre>

<p>When building, this <a href="http://i.stack.imgur.com/6xcfC.png" rel="nofollow">directory structure</a> is is created inside <code>${PROJECT_SOURCE_DIR}/external/</code></p>

<p>Although the cmake files exist to download and extract the project, these actions never occur.  What am I doing wrong here?</p>