$(filter $(subst *,%,$2),$d))
SRC := $(call rwildcard,src/,*.rs)
-LIB := target/$(shell rustc --crate-file-name src/lib.rs --crate-type rlib)
+LIB := target/$(shell rustc --print-file-name src/lib.rs)
ifeq ($(LIB),target/)
# We may not have rustc or the lib.rs file may be broken.
# But don't break the rules on that account.