cubicweb #1805233 [dataimport] display errors crashes with IndexError [deprecated]

When I run my import script and some exceptions have been caughts by datatimport, I am prompted to tell if I want to display the errors. If I say "yes" the program crashes with IndexError because len(error) is 1 and the error display routine tries to print error[1].

prioritynormal
typebug
done in<not specified>
load0.000
load left0.000
closed by<not specified>