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=9af6fdf861b06b7d1be9911ea19f9cb97c2689e4'>root</a>/<a href='/guix/log/gnu?id=9af6fdf861b06b7d1be9911ea19f9cb97c2689e4'>gnu</a>/<a href='/guix/log/gnu/tests?id=9af6fdf861b06b7d1be9911ea19f9cb97c2689e4'>tests</a>/<a href='/guix/log/gnu/tests/web.scm?id=9af6fdf861b06b7d1be9911ea19f9cb97c2689e4'>web.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/gnu/tests/web.scm?id=9af6fdf861b06b7d1be9911ea19f9cb97c2689e4&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-10-20 22:39:43 +0100'>2020-10-20</span></td><td><a href='/guix/commit/gnu/tests/web.scm?id=bdcf4d88d58798eca7811c8b1fbd4638168d05c3'>services: databases: Don't specify a default postgresql version.</a><span class='msg-avail'>...<span class='msg-tooltip'>Currently, if the postgresql package major version changes, this is going to
break the service upon upgrade, because PostgreSQL will reject the data files
from the differing major version of the service.

Because it's important to either keep running a particular major version, or
intentionally upgrade, I think the configuration would be better with no
default. I think this is also going to be helpful when trying to assist users
upgrading PostgreSQL.

* gnu/services/databases.scm (&lt;postgresql-configuration&gt;): Remove default for
postgresql.
(postgresql-service-type): Remove the default value.
* gnu/tests/databases.scm (%postgresql-os): Update accordingly.
* gnu/tests/guix.scm (%guix-data-service-os): Update accordingly.
* gnu/tests/monitoring.scm (%zabbix-os): Update accordingly.
* gnu/tests/web.scm (patchwork-os): Update accordingly.
* doc/guix.texi (PostgreSQL): Update accordingly.
</span></span></td><td>Christopher Baines</td></tr>
<tr><td><span title='2020-07-13 04:23:43 +0200'>2020-07-13</span></td><td><a href='/guix/commit/gnu/tests/web.scm?id=5cd9cd644ca493b230cb229e7c46641e94a4e2fa'>gnu: tests: Fix unbound variable.</a><span class='msg-avail'>...<span class='msg-tooltip'>Record type descriptors were made private in
a143e92446859bd1edc7a7aea85b2089c82c77da, but a usage of them was
forgotten in the tests files.

* gnu/tests/web.scm (patchwork-initial-database-setup-service): Use
accessors to access field values instead of unexported type descriptor.
</span></span></td><td>Julien Lepiller</td></tr>
<tr><td><span title='2020-04-21 16:33:21 +0200'>2020-04-21</span></td><td><a href='/guix/commit/gnu/tests/web.scm?id=aa7b3c6c0ecf7e27f0f6785908aa11e2268fa386'>tests: web: Explicitly wait for the HTTP port.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/tests/web.scm (run-webserver-test)["HTTP port ready"]: New test.
</span></span></td><td>Ludovic Courtès</td></tr>