Using --stack with xmin/xmax

[Luke]

Dear all,

I was wondering if I am doing something wrong when I use the --stack
option together with xmin/xmax.

I've added
options_by_histname = [
('rebin', 50, ['.*m3.*', '.*mttbar.*']),
('rebin', 5, ['.*diElectronMass.*']),
('xmax', 1000, ['.*diElectronMass.*']),
('xmin', 300, ['.*mttbar.*']),
('xmax', 3000, ['.*mttbar.*']),
('xmax', 1000, ['.*m3.*']),
]
to my rootplot_config.py which runs fine without the --stack option.
If I use:
rootplot rootplot_config.py
ElectronHad_4692.36pb_PFElectron_PFMuon_PF2PATJets_PFMET.root
TTJet_4692.36pb_PFElectron_PFMuon_PF2PATJets_PFMET.root
WJetsToLNu_4692.36pb_PFElectron_PFMuon_PF2PATJets_PFMET.root --data=1
--fill --stack

I get the following error:
http://pastebin.com/MLCEWkwq

I am using CMSSW_4_4_0_patch2 which ships rootplot version 2.2dev.

Am I doing something wrong or is it a bug worth reporting?

Thank you in advance,

Luke