gdbm: Fix multiple definitions error when building with clang

pkgs/development/libraries/gdbm/0001-Remove-duplicate-assignments.patch

@@ -0,0 +1,25 @@
+From 2c31a95d9e57a4308c5159c50e69b5c9178dee72 Mon Sep 17 00:00:00 2001
+From: Christian Kampka <christian@kampka.net>
+Date: Fri, 13 Nov 2020 16:52:12 +0100
+Subject: [PATCH] Remove duplicate assignments
+
+---
+ src/parseopt.c | 2 --
+ 1 file changed, 2 deletions(-)
+
+diff --git a/src/parseopt.c b/src/parseopt.c
+index 268e080..a4c8576 100644
+--- a/src/parseopt.c
++++ b/src/parseopt.c
+@@ -255,8 +255,6 @@ print_option_descr (const char *descr, size_t lmargin, size_t rmargin)
+ }
+ 
+ char *parseopt_program_name;
+-char *parseopt_program_doc;
+-char *parseopt_program_args;
+ const char *program_bug_address = "<" PACKAGE_BUGREPORT ">";
+ void (*parseopt_help_hook) (FILE *stream);
+ 
+-- 
+2.25.4
+

pkgs/development/libraries/gdbm/default.nix

@@ -11,6 +11,8 @@ stdenv.mkDerivation rec {
 
   doCheck = true; # not cross;
 
+  patches = [ ./0001-Remove-duplicate-assignments.patch ];
+
   # Linking static stubs on cygwin requires correct ordering.
   # Consider upstreaming this.