title: CMake rejects a second target_link_libraries talking about "keyword" vs "plain"
body: <p>I'm compiling a binary, and I want to add its dependency libraries in two different <code>target_link_libraries()</code> commands for various reasons.</p>
  
  <p>My commands look like this:</p>
  
  <pre><code>target_link_libraries(my_prog PRIVATE foo bar)
  target_link_libraries(my_prog baz)
  </code></pre>
  
  <p>and I get the error:</p>
  
  <pre><code>  The keyword signature for target_link_libraries has already been used with
    the target "my_prog".  All uses of target_link_libraries with a target
    must be either all-keyword or all-plain.
  
    The uses of the keyword signature are here:
  
     * tests/CMakeLists.txt:10 (target_link_libraries)
  </code></pre>
  
  <p>What does this mean? What should I do?</p>