Document -dsuppress-uniques

[ghc-hetmet.git] / docs / users_guide / debugging.xml

diff --git a/docs/users_guide/debugging.xml b/docs/users_guide/debugging.xml
index e00cd8f..d6a520a 100644 (file)
--- a/docs/users_guide/debugging.xml
+++ b/docs/users_guide/debugging.xml
@@ -423,6 +423,20 @@
 
       <varlistentry>
        <term>
+          <option>-dsuppress-uniques</option>
+          <indexterm><primary><option>-dsuppress-uniques</option></primary></indexterm>
+        </term>
+       <listitem>
+         <para>Suppress the printing of uniques in debugging output. This may make 
+         the printout ambiguous (e.g. unclear where an occurrence of 'x' is bound), but
+         it makes the output of two compiler runs have many fewer gratuitous differences,
+           so you can realistically apply <command>diff</command>.  Once <command>diff</command>
+         has shown you where to look, you can try again without <option>-dsuppress-uniques</option></para>
+       </listitem>
+      </varlistentry>
+
+      <varlistentry>
+       <term>
           <option>-dppr-user-length</option>
           <indexterm><primary><option>-dppr-user-length</option></primary></indexterm>
         </term>