Since upgrading to 7.4.1, if I &#39;cabal install&#39; successfully and then &#39;cabal install&#39; a second time without first doing a &#39;ghc-pkg unregister &lt;package-name&gt;&#39;, I get the following complaint:<br>

<br><blockquote style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex" class="gmail_quote">cabal: The install plan contains reinstalls which can break your GHC<br>installation. You can try --solver=modular for the new modular solver that<br>

chooses such reinstalls less often and also offers the --avoid-reinstalls<br>option. You can also ghc-pkg unregister the affected packages and run ghc-pkg<br>check to see the effect on reverse dependencies. If you know what you are<br>

doing you can use the --force-reinstalls option to override this reinstall<br>check.<br></blockquote><br>The only path I&#39;ve found so far that&#39;s willing to rebuild or even say nothing needs rebuilding (when nothing does) is to &#39;ghc-pkg unregister&#39; and then &#39;cabal install&#39; again. I&#39;m getting the same behavior on Red Hat 5 and Mac OS 10.6.8, both compiled from sources.<br>

<br>Does anyone know what&#39;s going on here?<br><br>-- Conal<br>