Add pkg-config as a GDAL dependency.

component/gdal/buildout.cfg

@@ -11,6 +11,7 @@ extends =
   ../libxml2/buildout.cfg
   ../openjpeg/buildout.cfg
   ../pcre/buildout.cfg
+  ../pkgconfig/buildout.cfg
   ../proj/buildout.cfg
   ../sqlite3/buildout.cfg
   ../xz-utils/buildout.cfg
@@ -38,7 +39,7 @@ configure-options =
   --with-xml2=yes
   --without-webp
 environment =
-  PATH=${xz-utils:location}/bin:%(PATH)s
+  PATH=${pkgconfig:location}/bin:${xz-utils:location}/bin:%(PATH)s
   CPPFLAGS=-I${pcre:location}/include
   LDFLAGS=-L${pcre:location}/lib -Wl,-rpath=${buildout:parts-directory}/${:_buildout_section_name_}/lib -Wl,-rpath=${proj:location}/lib -Wl,-rpath=${curl:location}/lib -Wl,-rpath=${geos:location}/lib -Wl,-rpath=${giflib:location}/lib -Wl,-rpath=${openjpeg:location}/lib -Wl,-rpath=${jbigkit:location}/lib -Wl,-rpath=${libexpat:location}/lib -Wl,-rpath=${libjpeg:location}/lib -Wl,-rpath=${libpng:location}/lib -Wl,-rpath=${libtiff:location}/lib -Wl,-rpath=${libxml2:location}/lib -Wl,-rpath=${openssl:location}/lib -Wl,-rpath=${pcre:location}/lib -Wl,-rpath=${sqlite3:location}/lib -Wl,-rpath=${zlib:location}/lib
   PKG_CONFIG_PATH=${libxml2:location}/lib/pkgconfig