libpcap: remove static library unless dontDisableStatic is set

pkgs/development/libraries/libpcap/default.nix

@@ -28,6 +28,12 @@ stdenv.mkDerivation rec {
     substituteInPlace configure --replace " -arch i386" ""
   '';
 
+  postInstall = ''
+    if [ "$dontDisableStatic" -ne "1" ]; then
+      rm -f $out/lib/libpcap.a
+    fi
+  '';
+
   meta = {
     homepage = "https://www.tcpdump.org";
     description = "Packet Capture Library";

pkgs/tools/networking/dsniff/default.nix

@@ -14,7 +14,7 @@ let
   };
   pcap = symlinkJoin {
     inherit (libpcap) name;
-    paths = [ libpcap ];
+    paths = [ (libpcap.overrideAttrs(old: { dontDisableStatic = true; })) ];
     postBuild = ''
       cp -rs $out/include/pcap $out/include/net
       # prevent references to libpcap