anchor.diff:    </tr>
     <tr>
       <th><code>BUILDKITE_BUILD_ID</code></th>
  -    <td>The UUID of the original build this was rebuilt from. <p class="Docs__api-param-eg"><em>Example:</em> <code>"4735ba57-80d0-46e2-8fa0-b28223a86586"</code>, or <code>""</code> if not a rebuild.</p></td>
  +    <td>The UUID of the build. <p class="Docs__api-param-eg"><em>Example:</em> <code>"4735ba57-80d0-46e2-8fa0-b28223a86586"</code>, or <code>""</code> if not a rebuild.</p></td>
     </tr>
     <tr>
       <th><code>BUILDKITE_BUILD_NUMBER</code></th>
  
positive.code:   </tr>
  </tbody>
  </table>
  
  Bootstrap vars:
  BUILDKITE_DISABLE_GIT_SUBMODULES
  BUILDKITE_REFSPEC
  
  ## Defining your own
  
  
negative.code:   </tr>
    <tr>
      <th><code>BUILDKITE_PULL_REQUEST_REPO</code></th>
      <td>The repository URL of the pull request. <p class="Docs__api-param-eg"><em>Example:</em> <code>"git://github.com/acme-inc/my-project.git"</code>, or <code>""</code> if not a pull request.</p></td>
    </tr>
    <tr>
      <th><code>BUILDKITE_REBUILT_FROM_BUILD_ID</code></th>
  