Add help to a makefile. Not my own, but I've lost the source.
## This help
help:
$(info Available targets)
@awk '/^[a-zA-Z\-\_0-9]+:/ { \
nb = sub( /^## /, "", helpMsg ); \
if(nb == 0) { \
helpMsg = $$0; \
nb = sub( /^[^:]*:.* ## /, "", helpMsg ); \
} \
if (nb) { \
printf "\033[1;31m%-" width "s\033[0m %s\n", $$1, helpMsg; \
} \
} \
{ helpMsg = $$0 }' \
width=$$(grep -o '^[a-zA-Z_0-9]\+:' $(MAKEFILE_LIST) | wc -L) \
$(MAKEFILE_LIST)