Fix Perl module Module::Pluggable such that it can find plugins that live in
symlinked directories.

Patch borrowed/adapted from Nixpkgs.

--- Module-Pluggable-5.2/lib/Module/Pluggable/Object.pm   2015-04-08 23:28:48.120164135 -0500
+++ Module-Pluggable-5.2/lib/Module/Pluggable/Object.pm   2015-04-08 23:30:27.032166704 -0500
@@ -164,7 +164,7 @@
         my $sp = catdir($dir, (split /::/, $searchpath));

         # if it doesn't exist or it's not a dir then skip it
-        next unless ( -e $sp && -d _ ); # Use the cached stat the second time
+        next unless ( -e $sp );

         my @files = $self->find_files($sp);

@@ -279,7 +279,7 @@
                              (my $path = $File::Find::name) =~ s#^\\./##;
                              push @files, $path;
                            }
-                      }, $search_path );
+                      }, "$search_path/." );
     }
     #chdir $cwd;
     return @files;='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=18321fe7c72442564e814cbe2636d4d18e87251a'>refs</a><a class='active' href='/guix/log/gnu/tests.scm'>log</a><a href='/guix/tree/gnu/tests.scm?id=18321fe7c72442564e814cbe2636d4d18e87251a'>tree</a><a href='/guix/commit/gnu/tests.scm?id=18321fe7c72442564e814cbe2636d4d18e87251a'>commit</a><a href='/guix/diff/gnu/tests.scm?id=18321fe7c72442564e814cbe2636d4d18e87251a'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/tests.scm'>
<input type='hidden' name='id' value='18321fe7c72442564e814cbe2636d4d18e87251a'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=18321fe7c72442564e814cbe2636d4d18e87251a'>root</a>/<a href='/guix/log/gnu?id=18321fe7c72442564e814cbe2636d4d18e87251a'>gnu</a>/<a href='/guix/log/gnu/tests.scm?id=18321fe7c72442564e814cbe2636d4d18e87251a'>tests.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.scm?id=18321fe7c72442564e814cbe2636d4d18e87251a&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-04-21 16:16:38 +0200'>2023-04-21</span></td><td><a href='/guix/commit/gnu/tests.scm?id=a09c7da8f8d8e732f969cf0a09aaa78f87032ab1'>tests: Fork and exec a new Guile for the marionette REPL.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-05-18 22:29:54 +0200'>2022-05-18</span></td><td><a href='/guix/commit/gnu/tests.scm?id=9a5d68692314bebd16dbcdc0d4e4e52fa4d5812f'>services: Add more description fields.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-08-29 01:05:26 -0400'>2021-08-29</span></td><td><a href='/guix/commit/gnu/tests.scm?id=da4e40948326387d5bcda58783914d5f9ce8b095'>Migrate to the new 'targets' field of bootloader-configuration.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>