Parallel make not working the way I expect...

[David Wuertele]

Here is my makefile:

LOTS_OF_FILES := one two three four five six

all: $(LOTS_OF_FILES)

COMMAND_WHICH_BUILDS_LOTS_OF_FILES := for file in $(LOTS_OF_FILES); do echo
hello >> $$file; done

$(LOTS_OF_FILES): Makefile
        $(COMMAND_WHICH_BUILDS_LOTS_OF_FILES)

clean:
        rm -rf $(LOTS_OF_FILES)

Here is the output:

$ make clean; make -j2
rm -rf one two three four five six
for file in one two three four five six; do echo hello >> $file; done
for file in one two three four five six; do echo hello >> $file; done

Why does the "COMMAND_WHICH_BUILDS_LOTS_OF_FILES" get run twice?

The strange thing is that this is not predictable:  sometimes, the "COMMAND..."
only gets run once.  I see it get run twice about 70% of the time on my system.

Dave