<command>ghc</command> traces the dependencies, just like <command>ghc --make</command>
(a new feature in GHC 6.4).</para>
+ <para>Note that <literal>ghc -M</literal> needs to find a <emphasis>source
+ file</emphasis> for each module in the dependency graph, so that it can
+ parse the import declarations and follow dependencies. Any pre-compiled
+ modules without source files must therefore belong to a
+ package<footnote><para>This is a change in behaviour relative to 6.2 and
+ earlier.</para>
+ </footnote>.</para>
+
<para>By default, <command>ghc -M</command> generates all the
dependencies, and then concatenates them onto the end of
<filename>makefile</filename> (or