KeyError if index has nonexistent columnname

[fschloesser]

If the user specifies a column in as index that doesn't exist a KeyError gets thrown.
What is the way to handle this? We could
a) throw an error (that explains the problem better to the user than now) and abort or
b) warn and try to fix this by either deleting the faulty column specifier or generating a new index from scratch.
I would do variant a)

[fschloesser]

to reproduce run this eval file with the benchmarkdata:

<?xml version="1.0" ?>
<Evaluation defaultgroup="SCIP" index="ProblemName Indic Solver" indexsplit="1">
	<Column active="True" origcolname="Status" reduction="meanOrConcat" />
	<FilterGroup filtertype="intersection" name="all">
		<Filter anytestrun="one" expression1="SolvingTime" expression2="10" operator="ge"/>
	</FilterGroup>
</Evaluation>

[GregorCH]

Let's wait with that until I have finished the reduction index #21