title: Android Studio, download soruces android-27 to target latest SDK
body: <p>To start a new project, I want to target the latest SDK (taking advantage of the fresh start).
  But, I also want to have access to the Android source code to be able to read the code of android classes (like AsyncTask, just as an example).
  I'm targeting SDK 27 on gradle and also using compileSdkVersion 27.
  I've tried by different ways (as indicated <a href="https://stackoverflow.com/questions/38714165/all-packages-are-not-available-for-download-error-in-android" title="question referenced">here</a>, <a href="https://stackoverflow.com/questions/45527767/android-api-26-platform-not-found-package-not-available-for-download" title="question referenced">here</a> and <a href="https://stackoverflow.com/questions/42960007/package-id-platform-android-o-not-available" title="question referenced">here</a>) but I can't seem to download those sources.</p>
  
  <p>When I try to browse an Android class like AsyncTask for example, I get the message:</p>
  
  <blockquote>
    <p>Decompiled .class file, bytecode version: 52.0 (Java 8)<br>
    Sources for 'Android API 27 Platform' not found.</p>
  </blockquote>
  
  <p>Even after clicking the <em>Download</em> and then the <em>Refresh (if already downloaded)</em> links (which is the most intuitive thing to do) I still can't see the source code of any Android class.</p>
  
  <p>This is an issue only for API 27. I'm able to download sources for all other API versions.</p>
  
  <p>Is this because of API 27 being the latest one?</p>
  
  <p>I want to avoid targeting 26. Is it possible to download those sources? Has anyone been able to do it so far?</p>
  
  <p>If someone knows how to do this so far, that would be very helpful. Thanks.</p>
  
  <p>I'm using Android Studio 3.0 and the download option for API 27 source is not available:</p>
  
  <p><a href="https://i.stack.imgur.com/8KWyP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/8KWyP.png" alt="Sources for API 27 not available"></a><a href="https://i.stack.imgur.com/Dhpt8.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Dhpt8.png" alt="No option to download sources"></a></p>
  
  <p><strong>UPDATE</strong>  </p>
  
  <p>As indicated by the accepted answer, the problem was the API Level 27 being a dev preview back then, the problem got resolved with time (once the official release happened). This update may be useful for people facing similar problems when targeting the latest available API version.</p>