title: Makefile : Clock skew detected
body: <p>My problem is whenever I try to compile using Makefile I get the following :</p>
  
  <pre><code>make: Warning: File `Board.c' has modification time 1.3e+03 s in the future
  gcc -Wall -c -Wvla -lm Board.c -o Board.o
  gcc -Wall -c -Wvla -lm PlayBoard.c -o PlayBoard.o
  gcc -lm ErrorHandle.o Board.o PlayBoard.o -g -o PlayBoard
  make: warning:  Clock skew detected.  Your build may be incomplete.
  </code></pre>
  
  <p>My Makefile is :</p>
  
  <pre><code>CC = gcc
  FLAGS = -Wall -c -Wvla
  
  PlayBoard: ErrorHandle.o Board.o PlayBoard.o
      $(CC) -lm ErrorHandle.o Board.o PlayBoard.o -g -o $@
  
  PlayBoard.o: PlayBoard.c Board.o
      $(CC) $(FLAGS) -lm PlayBoard.c -o $@
  
  Board.o : ErrorHandle.o Board.c Board.h
      $(CC) $(FLAGS) -lm Board.c -o $@
  
  .PHONY : clean
  
  clean:
      rm -f Board.o PlayBoard.o PlayBoard
  
  all : PlayBoard
  </code></pre>
  
  <p>Thank you for your help.</p>