Merge pull request #39125 from mpickering/darwin-saga

SAGA, SAGA LTS release, dependencies and QGIS SAGA plugin

pkgs/applications/gis/qgis/default.nix

@@ -1,14 +1,15 @@
 { stdenv, fetchurl, fetchpatch, gdal, cmake, qt4, flex, bison, proj, geos, xlibsWrapper, sqlite, gsl
 , qwt, fcgi, python2Packages, libspatialindex, libspatialite, qscintilla, postgresql, makeWrapper
 , qjson, qca2, txt2tags, openssl, darwin, pkgconfig
-, withGrass ? true, grass, IOKit, ApplicationServices
+, withGrass ? true, grass, saga, IOKit, ApplicationServices
 }:
 
 stdenv.mkDerivation rec {
   name = "qgis-2.18.22";
 
   buildInputs = [ gdal qt4 flex openssl bison proj geos xlibsWrapper sqlite gsl qwt qscintilla
-    fcgi libspatialindex libspatialite postgresql qjson qca2 txt2tags pkgconfig ]
+    fcgi libspatialindex libspatialite postgresql qjson qca2 txt2tags pkgconfig
+    saga ]
   ++
     (stdenv.lib.optionals stdenv.isDarwin [IOKit ApplicationServices])
   ++
@@ -68,6 +69,8 @@ stdenv.mkDerivation rec {
       # Necessary for QGIS to find the correct default GRASS path
       # Plugins look for gdal tools like deminfo on the PATH
       ${stdenv.lib.optionalString withGrass "ln -sf ${grass} $out/QGIS.app/Contents/MacOS/grass"}
+      # Necessary for QGIS to find the right SAGA installation
+      ln -sf ${saga}/bin/saga_cmd $out/QGIS.app/Contents/MacOS/bin/saga_cmd
       for file in $(find $out -type f -name "QGIS"); do
         wrapProgram "$file" \
           --prefix DYLD_LIBRARY_PATH : "${qwt}/lib" \