perl-net-dns-resolver-programmable used the undocumented and internal
method Net::DNS::rcodesbyname [0], and that interface is no longer
exposed.

This patch, copied from [1], makes the program check for the existence
of the method before trying to use it.

[0]
<https://rt.cpan.org/Public/Bug/Display.html?id=95901>

[1]
<https://rt.cpan.org/Public/Bug/Display.html?id=95901#txn-1575108>

diff --git a/lib/Net/DNS/Resolver/Programmable.pm b/lib/Net/DNS/Resolver/Programmable.pm
index 1af72ce..e09a2f0 100644
--- a/lib/Net/DNS/Resolver/Programmable.pm
+++ b/lib/Net/DNS/Resolver/Programmable.pm
@@ -203,8 +203,10 @@ sub send {
     if (defined(my $resolver_code = $self->{resolver_code})) {
         ($result, $aa, @answer_rrs) = $resolver_code->($domain, $rr_type, $class);
     }
-    
-    if (not defined($result) or defined($Net::DNS::rcodesbyname{$result})) {
+
+    if (not defined($result)
+         or defined($Net::DNS::Parameters::rcodebyname{$result})
+         or defined($Net::DNS::rcodesbyname{$result})) {
         # Valid RCODE, return a packet:
         
         $aa     = TRUE      if not defined($aa);
8a'>refs</a><a class='active' href='/guix/log/gnu/packages/genealogy.scm'>log</a><a href='/guix/tree/gnu/packages/genealogy.scm?id=3b87e7ce525493c9b12aae3f651d966788794f8a'>tree</a><a href='/guix/commit/gnu/packages/genealogy.scm?id=3b87e7ce525493c9b12aae3f651d966788794f8a'>commit</a><a href='/guix/diff/gnu/packages/genealogy.scm?id=3b87e7ce525493c9b12aae3f651d966788794f8a'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/genealogy.scm'>
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<div class='path'>path: <a href='/guix/log/?id=3b87e7ce525493c9b12aae3f651d966788794f8a'>root</a>/<a href='/guix/log/gnu?id=3b87e7ce525493c9b12aae3f651d966788794f8a'>gnu</a>/<a href='/guix/log/gnu/packages?id=3b87e7ce525493c9b12aae3f651d966788794f8a'>packages</a>/<a href='/guix/log/gnu/packages/genealogy.scm?id=3b87e7ce525493c9b12aae3f651d966788794f8a'>genealogy.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/packages/genealogy.scm?id=3b87e7ce525493c9b12aae3f651d966788794f8a&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-12-13 17:48:25 +0100'>2021-12-13</span></td><td><a href='/guix/commit/gnu/packages/genealogy.scm?id=8394619baceb118df92e355377fd543bb1aa501a'>gnu: Simplify package inputs.</a><span class='msg-avail'>...<span class='msg-tooltip'>This commit was obtained by running:

  ./pre-inst-env guix style

without any additional argument.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-10-03 19:23:51 +0200'>2021-10-03</span></td><td><a href='/guix/commit/gnu/packages/genealogy.scm?id=792a688103e04b88dbbf128e1e2c0b15d5e3d119'>gnu: gramps: Update to 5.1.4.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/genealogy.scm (gramps): Update to 5.1.4.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2021-03-28 18:46:23 +0200'>2021-03-28</span></td><td><a href='/guix/commit/gnu/packages/genealogy.scm?id=1f6e870ea56d2d43a135973e6a8b4513ad9fb469'>gnu: gramps: Update to 5.1.3.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/genealogy.scm (gramps): Update to 5.1.3.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>