MACS2 callpeak AttributeError: 'Namespace'

[hello_world4]

Hey all,
I am trying to run macs2 callpeak, with this command line

GEN_SIZE=0.4379e9
PVALUE=1e-5
macs2 callpeak -t "M1.bam" -c "IM.bam" -n "IM-M1_macs_p05" -f BAM -g "$GEN_SIZE" -p "$PVALUE" 2> IM-M1_macs_p05.log

and I get this error

Traceback (most recent call last):
File "/local/peakseq/MACS-2/bin/macs2", line 337, in <module>
main()
File "/local/peakseq/MACS-2/bin/macs2", line 54, in main
run( args )
File "/local/python/2.7-bis/lib/python2.7/site-packages/MACS2/callpeak.py", line 55, in run
options = opt_validate( args )
File "/local/python/2.7-bis/lib/python2.7/site-packages/MACS2/OptValidator.py", line 132, in opt_validate
options.peakxls = os.path.join( options.outdir, options.name+"_peaks.xls" )
AttributeError: 'Namespace' object has no attribute 'outdir'

Is there something wrong with my input? Do I miss something ?
Could you help me, please.

Thanks