narval #5740433 update setup.py to be more pip/venv friendly [validation pending]

prioritynormal
typeenhancement
done in4.2.0
load0.250
load left0.000
closed by#f5d7752dcb71 [pkg] fix setup.py for virtualenv/pip compatibility (closes #5740433)
patch[pkg] fix setup.py for virtualenv/pip compatibility (closes #5740433) [applied]