sbp/scalable — comment on commit 01d8d97a6d34b309699d4ad0e64f195219f34776
File: Makefile line 14
By nslater:

You're look at intermediary files here, which Make tries to be smart about.

.cf http://www.gnu.org/software/make/manual/make.html#Chained-Rules

"You can prevent automatic deletion of an intermediate file by marking it as a secondary file. To do this, list it as a prerequisite of the special target `.SECONDARY`. When a file is secondary, `make` will not create the file merely because it does not already exist, but `make` does not automatically delete the file. Marking a file as secondary also marks it as intermediate."