+ <para>If the environment variable <literal>GHC_PACKAGE_PATH</literal> is
+ set, and its value does not end in a separator (<literal>:</literal> on
+ Unix, <literal>;</literal> on Windows), then the last database is
+ considered to be the global database, and will be modified by default by
+ <literal>ghc-pkg</literal>. The intention here is that
+ <literal>GHC_PACKAGE_PATH</literal> can be used to create a virtual
+ package environment into which Cabal packages can be installed without
+ setting anything other than <literal>GHC_PACKAGE_PATH</literal>.</para>
+