make flags:    
building meta-build
sed "s@__prefix__@/nix/store/v0ka00w0jw9k4v5x8shxp4kvizz2hs6z-meta-build-env@g;\
	     s@__datadir__@/nix/store/v0ka00w0jw9k4v5x8shxp4kvizz2hs6z-meta-build-env/share@g;\
	     s@__PACKAGE__@meta-build-env@g" < meta-build.src > meta-build && chmod +x meta-build