Dependence on LC_NUMERIC settings

[anigamova]

Several users running Combine CMSSW based build at DESY reported incompatibility with the results obtained with containers, or those from lxplus. It appeared because of LC_NUMERIC=de_DE.UTF-8, the initial values of rateParameters (which was then frozen in the fit) was converted to int within doVar, because of differences in decimal points.

To start with we can add unset LC_NUMERIC to the instructions, but it is quite worrying that the results can depend on locale settings. I think the scope is much larger and RooStats are affected as well, so tagging @guitargeek here

[lauridsj]

Hi, to add to this, here is a minimal example in pyRoot:

import ROOT

ws = ROOT.RooWorkspace("ws")
ws.factory("x[3.33,0,5]")
ws.var("x").Print()

with LC_NUMERIC not set, it prints
RooRealVar::x = 3.33 L(0 - 5)

with LC_NUMERIC=de_DE.UTF-8 set, it prints instead:
RooRealVar::x = 3 L(0 - 5)

CMSSW version is 14_1_0_pre4, nothing else sourced.

[anigamova]

Created issue in ROOT: root-project/root#17797