I noticed a change in behaviour which I didn't find mentioned in (or an apparent consequence of) the listed backward-incompatible changes.
I have a pattern rule like "%.c %.h &: %.y" for a tool (Bison) that may generate two output files (.c and .h), but in some cases (depending on the option "--defines") only one of them (.c). With previous make versions, this rule would work in both cases, even if no .h file was generated (or expected): % cat Makefile all: foo.c %.c %.h &: %.y; touch "$@" foo.y: ; touch "$@" clean: ; rm -f foo.y foo.c % make-4.3 touch "foo.y" touch "foo.c" % make-4.3 make-4.3: Nothing to be done for 'all'. With the new version, make keeps remaking foo.c because foo.h does not exist: % make clean rm -f foo.y foo.c % make touch "foo.y" touch "foo.c" % make touch "foo.c" % make touch "foo.c" Now, it's not a problem to me, I'll use something like "%.c $(if $(...),,%.h) &: %.y" (which is arguably more correct, anyway), just wanted to let you know in case this change in behaviour was not intended.
