The problem with globbing is gratuitous matches. If a.cc depends on l.h and m.h, and b.cc only depends on m.h, doing a glob in the dependencies ( $(wildcard…)

The problem with globbing is gratuitous matches. If a.cc depends on l.h and m.h, and b.cc only depends on m.h, doing a glob in the dependencies ( $(wildcard…) ) will unnecessarily rebuild b.o if l.h changes.