On Thursday, November 22, 2012, Manuel M T Chakravarty  wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Simon Peyton-Jones &lt;<a href="javascript:;" onclick="_e(event, &#39;cvml&#39;, &#39;simonpj@microsoft.com&#39;)">simonpj@microsoft.com</a>&gt;:<br>

&gt; So the invariant I suggest is<br>
&gt; * If it&#39;d work in an empty database, it should work in any non-empty one<br>
&gt; * Installing X should never break the existing installation of Y<br>
<br>
This makes a lot of sense to me.</blockquote><div><br></div><div>We&#39;ve been working on this for some time and this property is sometimes known as hermetic builds. The first approximation will be sandbox in (as it is relatively easy to implement). Long term we want a write only Nix like package store.<span></span></div>