Use COPYFILE_DISABLE to prevent MacOS from including unnecessary dotfiles.

Makefile

@@ -133,7 +133,7 @@ PARTIAL_SUBMITFILES=$(filter-out $(TESTSOURCES), $(wildcard Makefile *.h *.cpp))
 $(PARTIAL_SUBMITFILE): $(PARTIAL_SUBMITFILES)
 	rm -f $(PARTIAL_SUBMITFILE) $(FULL_SUBMITFILE)
 	-dos2unix $(PARTIAL_SUBMITFILES)
-	tar -vczf $(PARTIAL_SUBMITFILE) $(PARTIAL_SUBMITFILES)
+	COPYFILE_DISABLE=true tar -vczf $(PARTIAL_SUBMITFILE) $(PARTIAL_SUBMITFILES)
 	@echo !!! WARNING: No test cases included. Use 'make fullsubmit' to include test cases. !!!
 
 # make fullsubmit.tar.gz - cleans, runs dos2unix, creates tarball including test cases
@@ -141,7 +141,7 @@ FULL_SUBMITFILES=$(filter-out $(TESTSOURCES), $(wildcard Makefile *.h *.cpp test
 $(FULL_SUBMITFILE): $(FULL_SUBMITFILES)
 	rm -f $(PARTIAL_SUBMITFILE) $(FULL_SUBMITFILE)
 	-dos2unix $(FULL_SUBMITFILES)
-	tar -vczf $(FULL_SUBMITFILE) $(FULL_SUBMITFILES)
+	COPYFILE_DISABLE=true tar -vczf $(FULL_SUBMITFILE) $(FULL_SUBMITFILES)
 	@echo !!! Final submission prepared, test cases included... READY FOR GRADING !!!
 
 # shortcut for make submit tarballs