title: Cmake Ninja error android. "missing and no known rule to make it" although file exists
body: <p>I keep getting a</p>
  <blockquote>
  <p>ninja: error: '/root/code/CalcLib/libCalcLibAndroidx86.a', needed by
  '/root/code/compcorpsdk/build/intermediates/cmake/prod/release/obj/x86/libJumboFFT.so',
  missing and no known rule to make it</p>
  </blockquote>
  <p>Although I checked both directories with the correct files exist and I believe I have the include-directories paths set up correctly in the CmakeList.txt.</p>
  <p><strong>CMakeLists.txt</strong></p>
  <pre><code>cmake_minimum_required(VERSION 3.4.1)
  
  set(
  P1 &quot;/root/code/CalcLib&quot;
  CACHE STRING &quot;&quot;
  )
  
  message(${ANDROID_ABI})
  
  file(GLOB CPP_FILES &quot;*.cpp&quot;)
  
  add_library(
  JumboFFT
  SHARED
  ${CPP_FILES}
  )
  
  include_directories(src/main/jni)
  include_directories(${P1})
  
  target_link_libraries(
  JumboFFT
  log
  android
  OpenSLES
  ${P1}/libCalcLibAndroid${ANDROID_ABI}.a
  )
  </code></pre>
  <p><strong>Gradle Assemble output</strong>
  <a href="https://i.stack.imgur.com/IWZWc.png" rel="nofollow noreferrer">Gradle Asemble output text</a></p>