title: PhpStorm showing "unvailable" breakpoint whereas execution is suspended
body: <p>I'm sometimes stuck while attempting to debug my code.
  Debug Session is active, code execution is suspended :</p>
  <p><a href="https://i.stack.imgur.com/ShKGB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ShKGB.png" alt="debug is on and smthg gets hit" /></a></p>
  <p>But I cannot see what really happens, as the breakpoint show &quot;unavailable&quot; (&quot;no parking&quot; symbol):</p>
  <p><a href="https://i.stack.imgur.com/zHTXb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zHTXb.png" alt="enter image description here" /></a></p>
  <p>Does anybody know about this sign ?</p>
  <p>I still haven't found any information about it on JetBrains sites... that's why I'm here :-)</p>
  <p>(PhpStorm 2020.3, using docker containers (linux containers) with Docker Desktop/ Windows 10)</p>
  <p>[EDIT] :
  I just noticed that &quot;break at first line in php script&quot; seem to be functioning though:</p>
  <p><a href="https://i.stack.imgur.com/TIpvs.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/TIpvs.png" alt="enter image description here" /></a></p>
  <p>But I have these weird breakpoints instead of red &quot;normal&quot; ones, and an highlighted line.</p>
  <p>I tried restarting my docker containers, same issue. This produces seemingly randomly and gets solved after a while ... (reboot ?...)</p>
  <p>[EDIT] <em>SOLVED</em>
  The path mapping (local&lt;-&gt;docker) for the root of my project was empty (how did it happen...) in my docker configuration in PhPStorm.
  I'm not sure how this problem occured, but I'll be able to solve it next time if it's back.</p>