Marcus Meissner <marcus@jet.franken.de> writes:

 Which is caused by these Makefile rules:

 mcy.tab.h: /home/marcus/projects/wine/tools/wmc/mcy.y
         $(BISON) -p mcy_ -o mcy.tab.c -d /home/marcus/projects/wine/tools/wmc/mcy.y
 mcy.tab.c: /home/marcus/projects/wine/tools/wmc/mcy.y mcy.tab.h
         $(BISON) -p mcy_ -o $@ /home/marcus/projects/wine/tools/wmc/mcy.y

 The same bison call will generate both mcy.tab.h and mcy.tab.c, but the rules race each other
 due to the timestamp of mcy.tab.h being too close to mcy.tab.c.

 A rule like:

 mcy.tab.h mcy.tab.c: /home/marcus/projects/wine/tools/wmc/mcy.y
         $(BISON) -p mcy_ -o mcy.tab.c -d /home/marcus/projects/wine/tools/wmc/mcy.y

 will also work. I will be sending a patch.

No, that doesn't work because both commands can run at the same time and
overwrite each other files. That's why the .tab.c needs a dependency on
the .tab.h.