Merge pull request #210980 from alyssais/libiconv-netbsd

libiconv: don't use libiconvReal on NetBSD

pkgs/top-level/all-packages.nix

@@ -21086,9 +21086,10 @@ with pkgs;
 
   libgsf = callPackage ../development/libraries/libgsf { };
 
-  # GNU libc provides libiconv so systems with glibc don't need to build
-  # libiconv separately. Additionally, Apple forked/repackaged libiconv so we
-  # use that instead of the vanilla version on that OS.
+  # GNU libc provides libiconv so systems with glibc don't need to
+  # build libiconv separately. Additionally, Apple forked/repackaged
+  # libiconv so we use that instead of the vanilla version on that OS,
+  # and BSDs include libiconv in libc.
   #
   # We also provide `libiconvReal`, which will always be a standalone libiconv,
   # just in case you want it regardless of platform.
@@ -21099,6 +21100,8 @@ with pkgs;
         else stdenv.cc.libc)
     else if stdenv.hostPlatform.isDarwin
       then darwin.libiconv
+    else if stdenv.hostPlatform.isNetBSD
+      then null
     else libiconvReal;
 
   glibcIconv = libc: let