for subdir in $$list; do \
if [ -x $$subdir/build -a ! -f .$$subdir -o $@ = clean ] ; \
then echo -n Building $$subdir... ; \
- cd $$subdir && output=`CXXFLAGS="$(CXXFLAGS)" ./build $@ 2>&1` ; \
+ cd $$subdir && output=$$(CXXFLAGS="$(CXXFLAGS)" ./build $@ 2>&1) ; \
if [ $$? -eq 0 ] ; \
then echo OK && touch ../.$$subdir ; \
else echo $$output && exit 1 ; \