-.depends: *.c lib/*.c lib/*.cc
- $(CXX) -M $(CPPFLAGS) $(NOTMUCH_DEPENDS_FLAGS) \
- $(NOTMUCH_CXX_DEPENDS_FLAGS) $^ > $@
--include .depends
+# Potentially speedup make clean, distclean and dataclean ; avoid
+# re-creating Makefile.config if it exists but configure is newer.
+ifneq ($(CLEAN_GOAL),)
+Makefile.config: | $(srcdir)/configure
+else
+Makefile.config: $(srcdir)/configure
+endif
+ifeq ($(configure_options),)
+ @echo ""
+ @echo "Note: Calling ./configure with no command-line arguments. This is often fine,"
+ @echo " but if you want to specify any arguments (such as an alternate prefix"
+ @echo " into which to install), call ./configure explicitly and then make again."
+ @echo " See \"./configure --help\" for more details."
+ @echo ""
+endif
+ $(srcdir)/configure $(configure_options)