default.nix

let
  rawfunc = import <nixpkgs>;
in
with rawfunc {};
{
  imagemagick1 = pkgs.callPackage ./imagemagick-old.nix {  };
  imagemagick2 = pkgs.callPackage ./imagemagick-new.nix {  };
}

imagemagick-new.nix

{ stdenv, lib, fetchurl, python, pkgconfig, zlib, glib, flex, bison, makeStaticLibraries, glibc, libtool, bzip2, libX11, libXext, libXt, fontconfig, freetype, ghostscript, libjpeg, lcms2, openexr, libpng\
, librsvg, libtiff, libxml2, openjpeg, libwebp }:

let
  cfg = {
    version = "6.9.4-10";
    sha256 = "a2c981ea80de0ed95135591d0e504a2427187594a5cb2342474f50d97e626a2d";
  };
in
stdenv.mkDerivation rec {
  name = "imagemagicknew";
  buildInputs = [ python pkgconfig zlib.static flex bison glibc.static zlib fontconfig freetype ghostscript libpng libtiff libxml2 ];
  inherit (cfg) version;
  src = fetchurl {
    urls = [
      "mirror://imagemagick/releases/ImageMagick-${version}.tar.xz"
    ];
    sha256 = "a2c981ea80de0ed95135591d0e504a2427187594a5cb2342474f50d97e626a2d";
  };
  enableParallelBuilding = true;
  configureFlags =
    [ "--with-frozenpaths" ]
    ++ [ "--with-gcc-arch=x86-64" ]
    ++ [ "--host=x86_64" ]
    ++ lib.optional (librsvg != null) "--with-rsvg"
    ++ lib.optionals (ghostscript != null)
      [ "--with-gs-font-dir=${ghostscript}/share/ghostscript/fonts"
        "--with-gslib"
      ]
    ;
  postInstall =	''                                                                                                                                                                                          
  for x in $out/bin/*; do mv -v $x ''${x}-1.4;done                                                                                                                                                          
  for x in $out/etc/ImageMagick-6/*; do mv -v $x ''${x}-1.4;done                                                                                                                                            
  '';
}

imagemagick-old.nix

{ stdenv, lib, fetchurl, python, pkgconfig, zlib, glib, flex, bison, makeStaticLibraries, glibc, libtool, bzip2, libX11, libXext, libXt, fontconfig, freetype, ghostscript, libjpeg, lcms2, openexr, libpng\
, librsvg, libtiff, libxml2, openjpeg, libwebp }:

let
  cfg = {
    version = "6.9.3-10";
    sha256 = "e33f021c879f31703f9e620f578ccf7d221a34941589da4bbe967b16a814336a";
  };
in
stdenv.mkDerivation rec {
  name = "imagemagickold";
  buildInputs = [ python pkgconfig zlib.static flex bison glibc.static zlib fontconfig freetype ghostscript libpng libtiff libxml2 ];
  inherit (cfg) version;
  src = fetchurl {
    urls = [
      "mirror://imagemagick/releases/ImageMagick-${version}.tar.xz"
    ];
    sha256 = "e33f021c879f31703f9e620f578ccf7d221a34941589da4bbe967b16a814336a";
  };
  enableParallelBuilding = true;
  configureFlags =
    [ "--with-frozenpaths" ]
    ++ [ "--with-gcc-arch=x86-64" ]
    ++ [ "--host=x86_64" ]
    ++ lib.optional (librsvg != null) "--with-rsvg"
    ++ lib.optionals (ghostscript != null)
      [ "--with-gs-font-dir=${ghostscript}/share/ghostscript/fonts"
        "--with-gslib"
      ]
    ;
  postInstall = ''                                                                                                                                                                                          
  for x in $out/bin/*; do mv -v $x ''${x}-1.2;done                                                                                                                                                          
  for x in $out/etc/ImageMagick-6/*; do mv -v $x ''${x}-1.2;done                                                                                                                                            
  '';
}