package01e.hs:2:1: error:
    Could not find module ‘Data.Map’
    It is a member of the hidden package ‘containers-0.5.7.1’.
    Use -v to see a list of the files searched for.

package01e.hs:3:1: error:
    Could not find module ‘Data.IntMap’
    It is a member of the hidden package ‘containers-0.5.7.1’.
    Use -v to see a list of the files searched for.