GCC rightfully complains about redefined variables, as iterator declarations
appear inside loops with a loop variable of the same name.

This patch has been sent upstream.

--- a/sets.cpp	2015-06-25 11:22:08.252821681 +0200
+++ b/sets.cpp	2015-06-25 11:22:23.239187985 +0200
@@ -768,11 +768,11 @@
       //////////////////////////////////////////////
       // Reset original missing status
 
-      vector<Individual*>::iterator i = PP->sample.begin();
-      while ( i != PP->sample.end() )
+      vector<Individual*>::iterator it = PP->sample.begin();
+      while ( it != PP->sample.end() )
 	{
-	  (*i)->missing = (*i)->flag;
-	  ++i;
+	  (*it)->missing = (*it)->flag;
+	  ++it;
 	}
 
       ////////////////////////////////////////////////

--- a/elf.cpp	2009-10-10 18:00:21.000000000 +0200
+++ b/elf.cpp	2015-06-25 11:34:06.136835756 +0200
@@ -1175,10 +1175,10 @@
 	  << setw(8) << gcnt << " "
 	  << setw(8) << (double)cnt / (double)gcnt << "\n";
 
-      map<int,int>::iterator i = chr_cnt.begin();
-      while ( i != chr_cnt.end() )
+      map<int,int>::iterator it = chr_cnt.begin();
+      while ( it != chr_cnt.end() )
 	{
-	  int c = i->first;
+	  int c = it->first;
 	  int x = chr_cnt.find( c )->second;
 	  int y = chr_gcnt.find( c )->second;
 	  
@@ -1189,7 +1189,7 @@
 	      << setw(8) << y << " "
 	      << setw(8) << (double)x / (double)y << "\n";
 	  
-	  ++i;
+	  ++it;
 	}
       
     }

--- plink-1.07-src/idhelp.cpp	2009-10-10 18:00:22.000000000 +0200
+++ plink-1.07-src/idhelp.cpp.patched	2015-06-25 11:37:39.387204086 +0200
@@ -772,12 +772,12 @@
       for (int j = 0 ; j < jointField.size(); j++ )
 	{
 	  set<IDField*> & jf = jointField[j];
-	  set<IDField*>::iterator j = jf.begin();
+	  set<IDField*>::iterator jit = jf.begin();
 	  PP->printLOG(" { ");
-	  while ( j != jf.end() )
+	  while ( jit != jf.end() )
 	    {
-	      PP->printLOG( (*j)->name + " " );
-	      ++j;
+	      PP->printLOG( (*jit)->name + " " );
+	      ++jit;
 	    }
 	  PP->printLOG(" }");
 	}
f='/guix/log/?id=c88a870e9c13c54adafc69855df2d00ed200782f'>root</a>/<a href='/guix/log/tests?id=c88a870e9c13c54adafc69855df2d00ed200782f'>tests</a>/<a href='/guix/log/tests/modules.scm?id=c88a870e9c13c54adafc69855df2d00ed200782f'>modules.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/tests/modules.scm?id=c88a870e9c13c54adafc69855df2d00ed200782f&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2017-05-25 14:25:17 +0200'>2017-05-25</span></td><td><a href='/guix/commit/tests/modules.scm?id=bfe5264aa10c1af64adc5c24d0cf091562e3e09c'>modules: Raise an error when a dependency could not be found.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/modules.scm (&amp;missing-dependency-error): New error condition.
(source-module-dependencies): Raise it when 'search-path' returns #f.
* tests/modules.scm ("&amp;missing-dependency-error"): New test.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2016-09-05 00:06:47 +0200'>2016-09-05</span></td><td><a href='/guix/commit/tests/modules.scm?id=7ca87354db53fd1e1a7a3dfeddb9a598ea064bbe'>Add (guix modules).</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/modules.scm, tests/modules.scm: New files.
* Makefile.am (MODULES, SCM_TESTS): Add them.
* doc/guix.texi (G-Expressions): Add an example of
'source-module-closure'.
</span></span></td><td>Ludovic Courtès</td></tr>