try easy catch of error in bash loop

Author: jeffjennings

Makefile

@@ -37,8 +37,8 @@ convert:
 	_paths=($(MODIFIED_RQT_PATHS)); \
 	for notebook in ${MODIFIED_NOTEBOOKS}; do \
 		echo Installing requirements from $${_paths[i]}; \
-		python -m pip install --force-reinstall -r $${_paths[i]} > /dev/null; \
-		nbcollection convert ${CONVERTFLAGS} ${FLAGS} $$notebook; \
+		! python -m pip install --force-reinstall -r $${_paths[i]} > /dev/null; \
+		! nbcollection convert ${CONVERTFLAGS} ${FLAGS} $$notebook; \
 		i=$$((i+1)); \
 	done
 
@@ -57,8 +57,8 @@ convertall:
 	_paths=($(ALL_RQT_PATHS)); \
 	for notebook in ${ALL_NOTEBOOKS}; do \
 		echo Installing requirements from $${_paths[i]}; \
-		python -m pip install --force-reinstall -r $${_paths[i]} > /dev/null; \
-		nbcollection convert ${CONVERTFLAGS} ${FLAGS} $$notebook; \
+		! python -m pip install --force-reinstall -r $${_paths[i]} > /dev/null; \
+		! nbcollection convert ${CONVERTFLAGS} ${FLAGS} $$notebook; \
 		i=$$((i+1)); \
 	done