title: makefile implicit rule override error
body: <p>When building try.img, the following makefile works,
  because it uses the implicit rule for %.o: %.c.
  But if I uncomment the last 3 lines, it does not work any more. 
  Any idea why?</p>
  
  <p>Thank you in advance for any help you may provide.</p>
  
  <pre><code>try.img: try.elf
      $(OBJCOPY) $&lt; -O binary $@
  
  %.elf: %.o %.ld %.symbols
      $(LD) $(LDFLAGS) -T $(@:.elf=.ld) $(@:.elf=.o) -o $@
  
  #%.o: %.c
  #   echo "abc"
  #   $(CC) $(CFLAGS) -c $&lt; -o %@
  </code></pre>