gem-config.mathematical: add lasem to rpath

Co-authored-by: Dylan Baker <dylan@pnwbakers.com>

pkgs/development/ruby-modules/gem-config/default.nix

@@ -18,7 +18,7 @@
 # (to make gems behave if necessary).
 
 { lib, fetchurl, writeScript, ruby, kerberos, libxml2, libxslt, python, stdenv, which
-, libiconv, postgresql, v8, clang, sqlite, zlib, imagemagick
+, libiconv, postgresql, v8, clang, sqlite, zlib, imagemagick, lasem
 , pkg-config , ncurses, xapian, gpgme, util-linux, tzdata, icu, libffi
 , cmake, libssh2, openssl, libmysqlclient, darwin, git, perl, pcre, gecode_3, curl
 , msgpack, libsodium, snappy, libossp_uuid, lxc, libpcap, xorg, gtk2, buildRubyGem
@@ -332,6 +332,7 @@ in
       flex
       pkg-config
       python3
+      patchelf
     ];
 
     buildInputs = [
@@ -356,12 +357,13 @@ in
             $out/${ruby.gemPath}/extensions/*/*/mathematical-${attrs.version}/gem_make.out
     '';
 
-    # For some reason 'mathematical.so' is missing cairo and glib in its RPATH, add them explicitly here
+    # For some reason 'mathematical.so' is missing cairo, glib, and
+    # lasem in its RPATH, add them explicitly here
     postFixup = lib.optionalString stdenv.isLinux ''
       soPath="$out/${ruby.gemPath}/gems/mathematical-${attrs.version}/lib/mathematical/mathematical.so"
-      ${patchelf}/bin/patchelf \
-        --set-rpath "${lib.makeLibraryPath [ glib cairo ]}:$(${patchelf}/bin/patchelf --print-rpath "$soPath")" \
-        "$soPath"
+      rpath="$(patchelf --print-rpath "$soPath")"
+      patchelf --set-rpath "${lib.makeLibraryPath [ lasem glib cairo ]}:$rpath" "$soPath"
+      patchelf --replace-needed liblasem.so liblasem-0.4.so "$soPath"
     '';
   };