title: Error aapt: Attribute "font" already defined with incompatible format. Original attribute defined here
body: <p>Following error message I get after updating supportlibs to 27.0.2 and compileVersion to 27</p>
  
  <pre><code>Error:(252, 5) Attribute "font" already defined with incompatible format.
  
  &gt; /home/ralfi/.gradle/caches/transforms-1/files-1.1/appcompat-v7-27.0.1.aar/644e31926a52609e6fffe47c9016abcc/res/values/values.xml
  &gt; Error:(252, 5) Attribute "font" already defined with incompatible
  &gt; format. Error:(252, 5) Original attribute defined here.
  &gt; /home/ralfi/ProjectFolder/android-example/app/build/intermediates/res/merged/internal/debug/values/values.xml
  &gt; Error:(631) Attribute "font" already defined with incompatible format.
  &gt; Error:(607) Original attribute defined here.
  </code></pre>
  
  <p>and this:</p>
  
  <pre><code>&gt; Error:java.util.concurrent.ExecutionException:
  &gt; com.android.ide.common.process.ProcessException: Error while executing
  &gt; process /opt/sdk/build-tools/26.0.2/aapt with arguments {package -f
  &gt; --no-crunch -I /opt/sdk/platforms/android-27/android.jar -M /home/ralfi/ProjectFolder/android-example/build/intermediates/manifests/full/internal/debug/AndroidManifest.xml
  &gt; -S /home/ralfi/ProjectFolder/android-example/build/intermediates/res/merged/internal/debug
  &gt; -m -J /home/ralfi/ProjectFolder/android-example/build/generated/source/r/internal/debug
  &gt; -F /home/ralfi/ProjectFolder/android-example/build/intermediates/res/internal/debug/resources-internalDebug.ap_
  &gt; -D /home/ralfi/ProjectFolder/android-example/build/intermediates/multi-dex/internal/debug/manifest_keep.txt
  &gt; --custom-package com.example.android -0 apk -c de,en --output-text-symbols /home/ralfi/ProjectFolder/android-example/build/intermediates/symbols/internal/debug
  &gt; --no-version-vectors}
  </code></pre>
  
  <ol>
  <li>Also putting supportLibs back to 25 tell me the same error. </li>
  <li>deleting build folders did not help</li>
  </ol>
  
  <p>EDIT in my values/attrs.xml the name font related occurs only as following:</p>
  
  <pre><code> &lt;declare-styleable name="Styleable"&gt;
          &lt;attr name="fontFace" format="string"/&gt;
          &lt;attr name="underlined" format="boolean"/&gt;
          &lt;attr name="android:lineSpacingMultiplier"/&gt;
          &lt;attr name="android:textSize"/&gt;
   &lt;/declare-styleable&gt;
  </code></pre>
  
  <p>and this tag:</p>
  
  <pre><code>&lt;attr name="minFontSize" format="reference|dimension"/&gt;
  </code></pre>
  
  <p><a href="https://files.fm/u/ctdc28pp" rel="nofollow noreferrer">Both Project and Module Gradle file</a></p>