title: cmake + TARGET_LINKER_FILE + add_library(INTERFACE IMPORTED)
body: <p>We currently have a cmake to build our application, we also use an external library that is defined that way (I have no control on this, it is generated by a tool called Conan, that we don't own !)</p>
  
  <pre><code>add_library(CONAN_PKG::libgpkg INTERFACE IMPORTED)
  </code></pre>
  
  <p>Later, I need to retrieve the path of the generated <code>.lib</code> file, most of the time I use a command like this:</p>
  
  <pre><code>set(MERGE_LIBS ${MERGE_LIBS} $&lt;TARGET_LINKER_FILE:libgpkg&gt;)        
  </code></pre>
  
  <p>I got this error message:</p>
  
  <pre><code>Error evaluating generator expression:
  
  $&lt;TARGET_LINKER_FILE:CONAN_PKG::sqlite3&gt;
  
  Target "CONAN_PKG::sqlite3" is not an executable or library.
  </code></pre>
  
  <p>Any idea to solve this issue?</p>