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;ix</td><td class='sub right'></td></tr></table>
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<tr><td><span title='2018-01-18 04:26:42 +0100'>2018-01-18</span></td><td><a href='/guix/commit/gnu/packages/toys.scm?id=5d5ad3da881566c2cfe01bd70e6d759f241fc73a'>gnu: Add sl.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
td></tr>
<tr><td><span title='2018-01-19 17:28:31 +0100'>2018-01-19</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=162a13740041f907f0ce5c2aa05b52b162b4e81a'>gnu: Consistently Write ‘file system(s)’.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2017-10-11 21:53:36 +0200'>2017-10-11</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=3bf42e22b36f719e9086ef92a74e665f8d4bef09'>gnu: gparted: Update to 0.30.0.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2017-09-22 12:21:09 +0200'>2017-09-22</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=9fc513ad101c802ad46dd65bc5886b6318abc096'>gnu: Use xxd instead of vim.</a><span class='msg-avail'>...</span></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2017-09-15 18:31:53 +0200'>2017-09-15</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=893f9d240a0a8b7b9f02a08d030618b15126554d'>gnu: Add pydf.</a><span class='msg-avail'>...</span></td><td>Stefan Reichör</td></tr>
<tr><td><span title='2017-09-01 23:52:18 +0200'>2017-09-01</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=d5909be93b1f7bc4689884d159d570e8470e054d'>gnu: gparted: Update home page.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2017-07-29 14:15:48 +0200'>2017-07-29</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=9f9b7a0d0123a5d04cdd0e19d3acea589452581c'>gnu: gptfdisk: Update to 1.0.3.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2017-07-28 01:02:39 +0200'>2017-07-28</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=73fe4552aa4958d4ea0d9ea0ef0326e112b22a92'>gnu: gptfdisk: Update description.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2017-07-25 23:58:34 +0200'>2017-07-25</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=ae03ee4274670e516b630ae12f8f4350289e8008'>gnu: fdisk: Update to 2.0.0a1.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2017-07-25 23:58:34 +0200'>2017-07-25</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=aa588d8a38e9333d7a4b1ef6984d3f58abdd9a8c'>gnu: sdparm: Update to 1.10.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2017-05-09 20:08:30 +0200'>2017-05-09</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=49393691d75a3334d3abb8e54f4e08ce47734f03'>gnu: Add f3.</a><span class='msg-avail'>...</span></td><td>Hartmut Goebel</td></tr>
<tr><td><span title='2017-02-24 16:39:41 +0100'>2017-02-24</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=6b08982d4a07e8ed9449e2927cf014c5f419f75c'>gnu: gparted: Update to 0.28.1.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2017-02-15 13:08:10 -0500'>2017-02-15</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=6fb9e069b05e12ff75dd098e7dc65a8c7007176c'>gnu: gptfdisk: Install the documentation.</a><span class='msg-avail'>...</span></td><td>Leo Famulari</td></tr>
<tr><td><span title='2017-02-15 01:32:32 +0100'>2017-02-15</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=20de37ef4d91f6ed547b040fa606b01c92f9e92f'>gnu: gparted: Update to 0.28.0.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2017-02-06 14:22:16 +0100'>2017-02-06</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=5f0f368630ba4c69e902aeab64edeb3d9f94b9b5'>gnu: dosfstools: Update to 4.1.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2017-02-06 12:03:27 +0100'>2017-02-06</span></td><td><a href='/guix/commit/gnu/packages/disk.scm?id=416c57f0711295a83dbde37b69e42fd899d08b47'>gnu: ddrescue: Update to 1.22.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>