consider TIMEOUT for cmake tests which is defaulted to only 300 seconds

dune/fem-dg/examples/advdiff/test/CMakeLists.txt

@@ -12,9 +12,11 @@ if( NOT FEMDG_FAST_TESTBUILD )
     add_executable( advdiffall ../main.cc )
     dune_target_enable_all_packages( advdiffall )
     dune_add_test( advdiffall )
+    set_tests_properties( advdiffall PROPERTIES TIMEOUT 3000 )
   else()
     dune_add_test( NAME advdiffall 
-                   SOURCES ../main.cc )
+                   SOURCES ../main.cc
+                   TIMEOUT 3000 ) 
   endif()
   add_code_generate_targets( advdiffall )
 endif()
@@ -25,9 +27,11 @@ if( DUNE_FEM_DG_VERSION VERSION_LESS "2.4.1" )
                COMPILE_DEFINITIONS "POLORDER=2" )
   dune_target_enable_all_packages( advdiff )
   dune_add_test( advdiff )
+  set_tests_properties( advdiff PROPERTIES TIMEOUT 3000 )
 else()
   dune_add_test( NAME advdiff 
                  SOURCES ../main.cc
-                 COMPILE_DEFINITIONS POLORDER=2 )
+                 COMPILE_DEFINITIONS POLORDER=2 
+                 TIMEOUT 3000 )
 endif()
 add_code_generate_targets( advdiff )