I'm new to SGE an I'm trying to run qmake with the simple following Makefile with our very new cluster:

merge.txt: job1.txt job2.txt job3.txt ...
    cat $^ > $@

job1.txt:
    sleep 1
    echo "Hello From " $@ > $@
    sleep 1

job2.txt:
    sleep 2
    echo "Hello From " $@ > $@
    sleep 2

job3.txt:
(...)

the following command raises an error:

qmake -l arch=lx24-amd64 -cwd -v PATH -- -j 4
sleep 1
dynamic mode
sleep 2
dynamic mode
sleep 3
dynamic mode
sleep 4
dynamic mode
critical error: can't resolve group
qmake: *** [job3.txt] Error 1
critical error: can't resolve group
qmake: *** [job2.txt] Error 1
critical error: can't resolve group
qmake: *** [job1.txt] Error 1
critical error: can't resolve group

what's wrong ?