[bugfix][METIS] disable METIS if header inclusion does not compile.

cmake/modules/DuneAlugridMacros.cmake

@@ -46,6 +46,16 @@ find_package(SIONlib)
 find_package(DLMalloc)
 find_package(ZOLTAN)
 find_package(METIS)
+if( METIS_FOUND )
+  # check if metis header compiles, otherwise disable METIS
+  check_cxx_source_compiles("
+  #include <metis.h>
+  int main () { return 0; }
+  " METIS_FOUND)
+  if(NOT METIS_FOUND )
+    unset(HAVE_METIS)
+  endif()
+endif ()
 
 # check for phtreads
 include(FindPThreads)