% scons -Q cc -o file1.o -c -I. file1.c cc -o file2.o -c -I. file2.c cc -o file3.o -c -I. file3.c cc -o prog file1.o file2.o file3.o % [CHANGE THE CONTENTS OF hello.h] % scons -Q --debug=explain scons: rebuilding `file1.o' because `hello.h' changed cc -o file1.o -c -I. file1.c scons: rebuilding `file3.o' because `hello.h' changed cc -o file3.o -c -I. file3.c scons: rebuilding `prog' because: `file1.o' changed `file3.o' changed cc -o prog file1.o file2.o file3.o