Merged and pushed. (But I didn't see any merges into the issue287 branch. Maybe
I misunderstood something? Or maybe you didn't push all changesets?)

Thanks for the additional pointer. I fixed the errors in the issue287
branch at bitbucket/digitaldump/downward.
Unfortunately I had to merge with default after I started fixing. Maybe
a diff with default shows the changes best.

Err...Issue249 is what I meant.

I was just coming to report this. This site details all the fixes you'll need 
(plus the change in the makefile for 4.4 --> 4.6: see Issue241):
- https://wiki.edubuntu.org/GCC4.6

FWIW, this looks like a missing #include. Errors like this crop up frequently
with new g++ versions because C++'s lack of an actual module system can mask
missing #includes (they are dragged in indirectly as an implementation detail of
the stdlib).

I think an
#include <cstddef>
in the right file might fix things.

I'll see if I can fix this.

Can you look into this? It'd probably be hard to debug it without access to the
OS...

$ ll /usr/bin/g++
lrwxrwxrwx 1 root root 7 2011-08-14 09:16 /usr/bin/g++ -> g++-4.6*

src/search$ make distclean
rm -rf .obj
rm -f *~ *.pyc
rm -f Makefile.depend gmon.out PROFILE core
rm -f sas_plan
rm -f downward-1 downward-1-debug downward-1-profile
jendrik@SAM:~/projects/Downward/fastr/src/search$ make
rm -f Makefile.temp
for source in planner.cc axioms.cc causal_graph.cc closed_list.cc combining_evaluator.cc domain_transition_graph.cc eager_search.cc enforced_hill_climbing_search.cc exact_timer.cc 
g_evaluator.cc globals.cc heuristic.cc ipc_max_heuristic.cc iterated_search.cc lazy_search.cc max_evaluator.cc operator.cc operator_cost.cc option_parser.cc pref_evaluator.cc 
relaxation_heuristic.cc search_engine.cc search_node_info.cc search_progress.cc search_space.cc state.cc successor_generator.cc sum_evaluator.cc timer.cc utilities.cc 
weighted_evaluator.cc open_lists/alternation_open_list.cc open_lists/open_list_buckets.cc open_lists/pareto_open_list.cc open_lists/standard_scalar_open_list.cc 
open_lists/tiebreaking_open_list.cc additive_heuristic.cc blind_search_heuristic.cc cea_heuristic.cc cg_heuristic.cc cg_cache.cc ff_heuristic.cc goal_count_heuristic.cc hm_heuristic.cc 
lm_cut_heuristic.cc max_heuristic.cc raz_mas_heuristic.cc raz_abstraction.cc raz_operator_registry.cc raz_variable_order_finder.cc landmarks/exploration.cc landmarks/h_m_landmarks.cc 
landmarks/lama_ff_synergy.cc landmarks/landmark_cost_assignment.cc landmarks/landmark_count_heuristic.cc landmarks/landmark_status_manager.cc landmarks/landmarks_graph_merged.cc 
landmarks/landmarks_graph.cc landmarks/landmarks_graph_rpg_exhaust.cc landmarks/landmarks_graph_rpg_sasp.cc landmarks/landmarks_graph_rpg_search.cc 
landmarks/landmarks_graph_zhu_givan.cc landmarks/util.cc learning/AODE.cc learning/classifier.cc learning/composite_feature_extractor.cc learning/feature_extractor.cc 
learning/maximum_heuristic.cc learning/naive_bayes_classifier.cc learning/PDB_state_space_sample.cc learning/probe_state_space_sample.cc learning/selective_max_heuristic.cc 
learning/state_space_sample.cc learning/state_vars_feature_extractor.cc ; do \
	    g++ -MM $source > Makefile.temp0; \
	    objfile=${source%%.cc}.o; \
	    sed -i -e "s@^[^:]*:@$objfile:@" Makefile.temp0; \
	    cat Makefile.temp0 >> Makefile.temp; \
	done
rm -f Makefile.temp0 Makefile.depend
sed -e "s@\(.*\)\.o:\(.*\)@.obj/\1.1.o:\2@" Makefile.temp >> Makefile.depend
sed -e "s@\(.*\)\.o:\(.*\)@.obj/\1.1.debug.o:\2@" Makefile.temp >> Makefile.depend
sed -e "s@\(.*\)\.o:\(.*\)@.obj/\1.1.profile.o:\2@" Makefile.temp >> Makefile.depend
rm -f Makefile.temp
g++ -g -m32  -Wall -W -Wno-sign-compare -Wno-deprecated -ansi -pedantic -Werror -DSTATE_VAR_BYTES=1 -I/usr/include/c++/4.4/i686-linux-gnu -Iext -O3 -DNDEBUG -fomit-frame-pointer -c 
planner.cc -o .obj/planner.1.o
g++ -g -m32  -Wall -W -Wno-sign-compare -Wno-deprecated -ansi -pedantic -Werror -DSTATE_VAR_BYTES=1 -I/usr/include/c++/4.4/i686-linux-gnu -Iext -O3 -DNDEBUG -fomit-frame-pointer -c 
axioms.cc -o .obj/axioms.1.o
g++ -g -m32  -Wall -W -Wno-sign-compare -Wno-deprecated -ansi -pedantic -Werror -DSTATE_VAR_BYTES=1 -I/usr/include/c++/4.4/i686-linux-gnu -Iext -O3 -DNDEBUG -fomit-frame-pointer -c 
causal_graph.cc -o .obj/causal_graph.1.o
g++ -g -m32  -Wall -W -Wno-sign-compare -Wno-deprecated -ansi -pedantic -Werror -DSTATE_VAR_BYTES=1 -I/usr/include/c++/4.4/i686-linux-gnu -Iext -O3 -DNDEBUG -fomit-frame-pointer -c 
closed_list.cc -o .obj/closed_list.1.o
g++ -g -m32  -Wall -W -Wno-sign-compare -Wno-deprecated -ansi -pedantic -Werror -DSTATE_VAR_BYTES=1 -I/usr/include/c++/4.4/i686-linux-gnu -Iext -O3 -DNDEBUG -fomit-frame-pointer -c 
combining_evaluator.cc -o .obj/combining_evaluator.1.o
g++ -g -m32  -Wall -W -Wno-sign-compare -Wno-deprecated -ansi -pedantic -Werror -DSTATE_VAR_BYTES=1 -I/usr/include/c++/4.4/i686-linux-gnu -Iext -O3 -DNDEBUG -fomit-frame-pointer -c 
domain_transition_graph.cc -o .obj/domain_transition_graph.1.o
g++ -g -m32  -Wall -W -Wno-sign-compare -Wno-deprecated -ansi -pedantic -Werror -DSTATE_VAR_BYTES=1 -I/usr/include/c++/4.4/i686-linux-gnu -Iext -O3 -DNDEBUG -fomit-frame-pointer -c 
eager_search.cc -o .obj/eager_search.1.o
g++ -g -m32  -Wall -W -Wno-sign-compare -Wno-deprecated -ansi -pedantic -Werror -DSTATE_VAR_BYTES=1 -I/usr/include/c++/4.4/i686-linux-gnu -Iext -O3 -DNDEBUG -fomit-frame-pointer -c 
enforced_hill_climbing_search.cc -o .obj/enforced_hill_climbing_search.1.o
g++ -g -m32  -Wall -W -Wno-sign-compare -Wno-deprecated -ansi -pedantic -Werror -DSTATE_VAR_BYTES=1 -I/usr/include/c++/4.4/i686-linux-gnu -Iext -O3 -DNDEBUG -fomit-frame-pointer -c 
exact_timer.cc -o .obj/exact_timer.1.o
g++ -g -m32  -Wall -W -Wno-sign-compare -Wno-deprecated -ansi -pedantic -Werror -DSTATE_VAR_BYTES=1 -I/usr/include/c++/4.4/i686-linux-gnu -Iext -O3 -DNDEBUG -fomit-frame-pointer -c 
g_evaluator.cc -o .obj/g_evaluator.1.o
In file included from option_parser_util.h:9:0,
                 from option_parser.h:40,
                 from g_evaluator.cc:2:
ext/tree.hh:102:13: Fehler: »ptrdiff_t« bezeichnet keinen Typ
make: *** [.obj/g_evaluator.1.o] Fehler 1