Issue with dependency files using Makefiles; file.d exist

Question

I have the following sub-section of makefile that's used to generate the .d files

 -include $(wildcard $(patsubst %,$(OBJ_PATH)/%.d,$(basename $(SRCS))))
 
 
%.o: %.cpp
          @$(CC) -I$(INCLUDE_PATH) $(CFLAGS) $< -MM -MT $(@:.d=.o) > $(OBJ_PATH)/$(notdir $*.d)
          ${CC} -I$(INCLUDE_PATH) $(CFLAGS) -c $< -o $(OBJ_PATH)/$(notdir $@)

Sometimes when I build the project, I get the following error /bin/sh: /path/to/my/build/dir/file.d: File exists, although .d files does not exist.

Then I keep getting this error, the only way to get rid of it is to remove the whole enclosing directory and use git restore and the system will build successfully.

---

System info:

• git version 2.27.0
• GNU Make 4.2.1
• Red Hat Enterprise Linux 8.5 (Ootpa)
• Free inodes: 426798634

Answer 1

You should remove the @ from your line that creates the .d file, so you can see what the command line actually is. It's always a bad idea to add @ before your makefile is working 100% correctly. Then you could cut and paste a full failure example into your question, including the command that generated the error message.

Your build lines are not right. During the compilation, you need to use $@ not $(OBJ_PATH)/$(notdir $@). It's always wrong to build a file that is not exactly $@.

During the creation of the dependency file $(@:.d=.o) is useless because $@ is already set to xxx.o so changing the .d suffix to .o doesn't do anything. You should just use -MT $@ here.

You can replace $(OBJ_PATH)/$(notdir $*.d) with the simpler %*.d.

This error is being shown by the shell and there's really no way we can understand what the problem is with the info given. Why would the shell give a "File exists" error when you use ">" to overwrite it?

I have a suspicion that it's not actually this command that is generating that error.