sbp/scalable — comment on commit 01d8d97a6d34b309699d4ad0e64f195219f34776
File: Makefile line 4
By sbp:

Only in GNU make. As the GNU make [manual says](http://www.gnu.org/software/make/manual/make.html#Makefile-Basics):

Every Makefile should contain this line:

SHELL = /bin/sh

to avoid trouble on systems where the SHELL variable might be inherited from the environment.